GHSA-q3hc-j9x5-mp9m

Withdrawn Advisory: ImageMagick has a use-after-free/double-free risk in Options::fontFamily when clearing family

## Withdrawn Advisory This advisory has been withdrawn because it does not affect the ImageMagick project's NuGet packages. ### Original Description We believe that we have discovered a potential security vulnerability in ImageMagick’s Magick++ layer that manifests when `Options::fontFamily` is invoked with an empty string. **Vulnerability Details** - Clearing a font family calls `RelinquishMagickMemory` on `_drawInfo->font`, freeing the font string but leaving `_drawInfo->font` pointing to freed memory while `_drawInfo->family` is set to that (now-invalid) pointer. Any later cleanup or reuse of `_drawInfo->font` re-frees or dereferences dangling memory. - `DestroyDrawInfo` and other setters (`Options::font`, `Image::font`) assume `_drawInfo->font` remains valid, so destruction or subsequent updates trigger crashes or heap corruption. ```cpp if (family_.length() == 0) { _drawInfo->family=(char *) RelinquishMagickMemory(_drawInfo->font); DestroyString(RemoveImageOption(imageInfo(),"family")); } ``` - **CWE-416 (Use After Free):** `_drawInfo->font` is left dangling yet still reachable through the Options object. - **CWE-415 (Double Free):** DrawInfo teardown frees `_drawInfo->font` again, provoking allocator aborts. **Affected Versions** - Introduced by commit `6409f34d637a34a1c643632aa849371ec8b3b5a8` (“Added fontFamily to the Image class of Magick++”, 2015-08-01, blame line 313). - Present in all releases that include that commit, at least ImageMagick 7.0.1-0 and later (likely late 6.9 builds with Magick++ font family support as well). Older releases without `fontFamily` are unaffected. **Command Line Triggerability** This vulnerability cannot be triggered from the command line interface. The bug is specific to the Magick++ C++ API, specifically the `Options::fontFamily()` method. The command-line utilities (such as `convert`, `magick`, etc.) do not expose this particular code path, as they operate through different internal mechanisms that do not directly call `Options::fontFamily()` with an empty string in a way that would trigger the use-after-free condition. **Proposed Fix** ```diff diff --git a/Magick++/lib/Options.cpp b/Magick++/lib/Options.cpp @@ void Magick::Options::fontFamily(const std::string &family_) - _drawInfo->family=(char *) RelinquishMagickMemory(_drawInfo->font); + _drawInfo->family=(char *) RelinquishMagickMemory(_drawInfo->family); ``` This frees only the actual family string, leaving `_drawInfo->font` untouched. Optionally nulling `_drawInfo->font` when clearing `font()` itself maintains allocator hygiene.