ImageSharp is a 2D graphics library. From 3.0.0 until 4.1.1, tiled TIFF decoding allocates a destination buffer using TileWidth but TiffDecompressorsFactory.Create constructs T4, T6, and Modified Huffman decompressors using the full frame width. TiffDecoderCore.DecodeTilesChunky can therefore direct frame-width fax scanlines into a tile-width buffer when TileWidth is smaller than ImageWidth. The mismatch causes attacker-controlled out-of-bounds writes, heap corruption, and process termination even with legal per-row run codes.
This tiled-path vulnerability is distinct from oversized CCITT runs in strip decoding. This issue is fixed in version 4.1.1.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
High
Complete denial of service
CVSS Vector v3.1
Weakness Type (CWE)
References 4
https://github.com/SixLabors/ImageSharp/commit/9ee7d1dd5b62d8c9f16cc755e7682838…
security-advisories@github.com
https://github.com/SixLabors/ImageSharp/pull/3176
security-advisories@github.com
https://github.com/SixLabors/ImageSharp/releases/tag/v4.1.1
security-advisories@github.com
https://github.com/SixLabors/ImageSharp/security/advisories/GHSA-v76p-62qx-wwq2
security-advisories@github.com