Use-after-free vulnerability in the GIFReadNextExtension function in lib/pngxtern/gif/gifread.c in OptiPNG 0.6.2 and earlier allows context-dependent attackers to cause a denial of service (application crash) via a crafted GIF image that causes the realloc function to return a new pointer, which triggers memory corruption when the old pointer is accessed.
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 Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Optipng | Optipng_project | * | 0.6.2 (including) |
| Optipng | Ubuntu | gutsy | * |
| Optipng | Ubuntu | hardy | * |
| Optipng | Ubuntu | intrepid | * |
| Optipng | Ubuntu | upstream | * |