CVE Vulnerabilities

CVE-2021-36086

Use After Free

Published: Jul 01, 2021 | Modified: Mar 24, 2026
CVSS 3.x
3.3
LOW
Source:
NVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
CVSS 2.x
2.1 LOW
AV:L/AC:L/Au:N/C:N/I:N/A:P
RedHat/V2
RedHat/V3
3.3 MODERATE
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
Ubuntu
LOW
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The CIL compiler in SELinux 3.2 has a use-after-free in cil_reset_classpermission (called from cil_reset_classperms_set and cil_reset_classperms_list).

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 Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.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
Debian_linuxDebian11.0 (including)11.0 (including)
Red Hat Enterprise Linux 8RedHatlibsepol-0:2.9-3.el8*
LibsepolUbuntubionic*
LibsepolUbuntuesm-infra/bionic*
LibsepolUbuntuesm-infra/focal*
LibsepolUbuntufocal*
LibsepolUbuntugroovy*
LibsepolUbuntuhirsute*
LibsepolUbuntuimpish*
LibsepolUbuntutrusty*
LibsepolUbuntuupstream*
LibsepolUbuntuxenial*

Potential Mitigations

References