CVE Vulnerabilities

CVE-2021-36085

Use After Free

Published: Jul 01, 2021 | Modified: Nov 21, 2024
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

The CIL compiler in SELinux 3.2 has a use-after-free in __cil_verify_classperms (called from __verify_map_perm_classperms and hashtab_map).

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 Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.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
Selinux Selinux_project 3.2 (including) 3.2 (including)
Red Hat Enterprise Linux 8 RedHat libsepol-0:2.9-3.el8 *
Libsepol Ubuntu bionic *
Libsepol Ubuntu esm-infra/bionic *
Libsepol Ubuntu esm-infra/focal *
Libsepol Ubuntu esm-infra/xenial *
Libsepol Ubuntu focal *
Libsepol Ubuntu groovy *
Libsepol Ubuntu hirsute *
Libsepol Ubuntu impish *
Libsepol Ubuntu upstream *
Libsepol Ubuntu xenial *

Potential Mitigations

References