compose.php in SquirrelMail 1.4.22 calls unserialize for the $mailtodata value, which originates from an HTTP GET request. This is related to mailto.php.

compose.php in SquirrelMail 1.4.22 calls unserialize for the $attachments value, which originates from an HTTP POST request. NOTE: the vendor disputes this because these two conditions for PHP object injection are not satisfied: existence of a PHP magic method (such as __wakeup or __destruct), and any attack-relevant classes must be declared before unserialize is called (or must be autoloaded).

squirrellyjs squirrelly v9.0.0 and fixed in v.9.0.1 was discovered to contain a code injection vulnerability via the component options.varName.

Squirrel.Windows is both a toolset and a library that provides installation and update functionality for Windows desktop applications. Installers generated by Squirrel.Windows 2.0.1 and earlier contain an issue with the DLL search path, which may lead to insecurely loading Dynamic Link Libraries. As a result, arbitrary code may be executed with the privilege of the user invoking the installer.

sqclass.cpp in Squirrel through 2.2.5 and 3.x through 3.1 allows an out-of-bounds read (in the core interpreter) that can lead to Code Execution. If a victim executes an attacker-controlled squirrel script, it is possible for the attacker to break out of the squirrel script sandbox even if all dangerous functionality such as File System functions has been disabled. An attacker might abuse this bug to target (for example) Cloud services that allow customization via SquirrelScripts, or distribute malware through video games that embed a Squirrel Engine.

Heap-based buffer overflow in sqbaselib.cpp in SQUIRREL 3.2 due to lack of a certain sq_reservestack call.

Squirrelly is a template engine implemented in JavaScript that works out of the box with ExpressJS. Squirrelly mixes pure template data with engine configuration options through the Express render API. By overwriting internal configuration options remote code execution may be triggered in downstream applications. This issue is fixed in version 9.0.0. For complete details refer to the referenced GHSL-2021-023.

XSS was discovered in SquirrelMail through 1.4.22 and 1.5.x through 1.5.2. Due to improper handling of RCDATA and RAWTEXT type elements, the built-in sanitization mechanism can be bypassed. Malicious script content from HTML e-mail can be executed within the application context via crafted use of (for example) a NOEMBED, NOFRAMES, NOSCRIPT, or TEXTAREA element.

The mail message display page in SquirrelMail through 1.4.22 has XSS via the formaction attribute.

The mail message display page in SquirrelMail through 1.4.22 has XSS via SVG animations (animate to attribute).