FFmpeg 0.5 < 9.0 Uninitialized Heap Memory Read in TIFF Decoder

FFmpeg versions from 0.5 up to, but not including, 9.0 contain an uninitialized heap memory disclosure vulnerability in the native TIFF decoder in libavcodec/tiff.c. An attacker who can cause FFmpeg to decode a crafted TIFF file can supply a valid Deflate-compressed strip that terminates successfully after producing fewer bytes than the declared strip requires. The tiff_unpack_zlib() function allocates a heap buffer sized for the full declared strip but copies all declared rows via memcpy() regardless of how many bytes zlib actually decompressed, causing unwritten bytes that can contain stale data from prior heap allocations to be incorporated into decoded image output and potentially exposing sensitive data in persistent services.

The product uses or accesses a resource that has not been initialized.

An attacker operating through local access may attempt exploitation when the stated preconditions are met. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.