🛡️ CVE-2021-43311 on Debian — upx-ucl

⚪ Unknown ✅ No Known Exploit OSV
N/A
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

A heap-based buffer overflow was discovered in upx, during the generic pointer 'p' points to an inaccessible address in func get_le32(). The problem is essentially caused in PackLinuxElf32::elf_lookup() at p_lx_elf.cpp:5382.

Distribution advisory

This page covers CVE-2021-43311 as tracked by Debian, for the package upx-ucl. The fix is available in version 4.2.2-1; earlier versions remain affected.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity none, availability high.

Affected software

DEBIAN-CVE-2021-43311 is recorded against 1 package.

  • upx-ucl (fixed in 4.2.2-1)

Timeline and source

Published on 24 March 2023 and last revised on 4 August 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

security-tracker.debian.org (Advisory)

CVE-2021-43311 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Details

Severity Unknown
CVSS Score N/A
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE N/A
Public Exploit ✅ No
Source OSV
Published 2023-03-24
Updated 2026-08-12
Modified 2026-08-04
Fix URL N/A

Affected Packages

Software From version Fixed in
upx-ucl — 4.2.2-1

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