ImageSharp is a 2D graphics library. From 2.0.0 until 4.1.2, the TIFF CCITT Group 3 encoder allocates an undersized compressed-data buffer for narrow 1-bit images. TiffCcittCompressor.Initialize does not reserve enough space for the row data and T4 end-of-line codes, and T4BitCompressor.CompressStrip reaches unchecked writes when TiffCompression.CcittGroup3Fax is selected directly or inherited from decoded TIFF metadata. An attacker-controlled encode or decode-and-re-encode flow can write beyond the logical output span, corrupt process memory, and terminate the process.
This issue is fixed in version 4.1.2.
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/a9498c6db3642ef92c712ebc81e70691…
security-advisories@github.com
https://github.com/SixLabors/ImageSharp/pull/3187
security-advisories@github.com
https://github.com/SixLabors/ImageSharp/releases/tag/v4.1.2
security-advisories@github.com
https://github.com/SixLabors/ImageSharp/security/advisories/GHSA-j9gm-c75j-xc9q
security-advisories@github.com