A call to ConformPixelInfo() in the SetImageAlphaChannel() routine of /MagickCore/channel.c caused a subsequent heap-use-after-free or heap-buffer-overflow READ when GetPixelRed() or GetPixelBlue() was called. This could occur if an attacker is able to submit a malicious image file to be processed by ImageMagick and could lead to denial of service. It likely would not lead to anything further because the memory is used as pixel data and not e.g. a function pointer. This flaw affects ImageMagick versions prior to 7.0.9-0.
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
| Link | Tags |
|---|---|
| https://github.com/ImageMagick/ImageMagick/issues/1723 | third party advisory exploit |
| https://bugzilla.redhat.com/show_bug.cgi?id=1891601 | issue tracking third party advisory patch |
| https://github.com/ImageMagick/ImageMagick/issues/1723#issuecomment-718275153 | third party advisory |