CVE Vulnerabilities

CVE-2021-33641

Use After Free

Published: Jan 20, 2023 | Modified: Apr 03, 2025
CVSS 3.x
7.8
HIGH
Source:
NVD
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS 2.x
RedHat/V2
RedHat/V3
4.4 MODERATE
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L
Ubuntu

When processing files, malloc stores the data of the current line. When processing comments, malloc incorrectly accesses the released memory (use after free).

Weakness

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 Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.

Affected Software

Name Vendor Start Version End Version
Byacc Openeuler * 1.9.20200330 (excluding)
Byacc Openeuler 2.0 (including) 2.0.20210808 (excluding)

Potential Mitigations

References