CVE Vulnerabilities

CVE-2021-36976

Use After Free

Published: Jul 20, 2021 | Modified: Nov 03, 2025
CVSS 3.x
6.5
MEDIUM
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
CVSS 2.x
4.3 MEDIUM
AV:N/AC:M/Au:N/C:N/I:N/A:P
RedHat/V2
RedHat/V3
6.5 MODERATE
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Ubuntu
MEDIUM
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libarchive 3.4.1 through 3.5.1 has a use-after-free in copy_string (called from do_uncompress_block and process_block).

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 Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.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

NameVendorStart VersionEnd Version
LibarchiveLibarchive3.4.1 (including)3.5.2 (including)
LibarchiveUbuntudevel*
LibarchiveUbuntuesm-infra/focal*
LibarchiveUbuntufocal*
LibarchiveUbuntugroovy*
LibarchiveUbuntuhirsute*
LibarchiveUbuntuimpish*
LibarchiveUbuntujammy*
LibarchiveUbuntutrusty*
LibarchiveUbuntuxenial*

Potential Mitigations

References