Heap-based Buffer Overflow Affecting libwebp-sys package, versions <0.9.3


Severity

Recommended
0.0
critical
0
10

CVSS assessment made by Snyk's Security Team. Learn more

Threat Intelligence

Exploit Maturity
Mature
EPSS
44.32% (98th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-RUST-LIBWEBPSYS-5922112
  • published12 Sept 2023
  • disclosed11 Sept 2023
  • creditApple SEAR, The Citizen Lab

Introduced: 11 Sep 2023

CVE-2023-4863  (opens in a new tab)
CWE-122  (opens in a new tab)

How to fix?

Upgrade libwebp-sys to version 0.9.3 or higher.

Overview

Affected versions of this package are vulnerable to Heap-based Buffer Overflow when the ReadHuffmanCodes() function is used. An attacker can craft a special WebP lossless file that triggers the ReadHuffmanCodes() function to allocate the HuffmanCode buffer with a size that comes from an array of precomputed sizes: kTableSize. The color_cache_bits value defines which size to use. The kTableSize array only takes into account sizes for 8-bit first-level table lookups but not second-level table lookups. libwebp allows codes that are up to 15-bit (MAX_ALLOWED_CODE_LENGTH). When BuildHuffmanTable() attempts to fill the second-level tables it may write data out-of-bounds. The OOB write to the undersized array happens in ReplicateValue.

Notes:

This is only exploitable if the color_cache_bits value defines which size to use.

This vulnerability was also published on libwebp CVE-2023-5129

Changelog:

2023-09-12: Initial advisory publication

2023-09-27: Advisory details updated, including CVSS, references

2023-09-27: CVE-2023-5129 rejected as a duplicate of CVE-2023-4863

2023-09-28: Research and addition of additional affected libraries

2024-01-28: Additional fix information

CVSS Scores

version 3.1