CVE-2021-36087

libsepol: heap-based buffer overflow in ebitmap_match_any()

Severity Score

3.3

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

The CIL compiler in SELinux 3.2 has a heap-based buffer over-read in ebitmap_match_any (called indirectly from cil_check_neverallow). This occurs because there is sometimes a lack of checks for invalid statements in an optional block.

El compilador CIL en SELinux 3.2 tiene una sobrelectura del búfer basada en el montón en ebitmap_match_any (llamado indirectamente desde cil_check_neverallow). Esto ocurre porque a veces no se comprueban las declaraciones no válidas en un bloque opcional

Red Hat Advanced Cluster Management for Kubernetes 2.2.10 images Red Hat Advanced Cluster Management for Kubernetes provides the capabilities to address common challenges that administrators and site reliability engineers face as they work across a range of public and private cloud environments. Clusters and applications are all visible and managed from a single console — with security policy built in. This advisory contains the container images for Red Hat Advanced Cluster Management for Kubernetes, which provide security fixes, bug fixes and container upgrades. Issues addressed include a bypass vulnerability.

*Credits: N/A

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

Low

Attack Vector

Local

Attack Complexity

Low

Authentication

None

Confidentiality

None

Integrity

None

Availability

Partial

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2021-07-01 CVE Reserved
2021-07-01 CVE Published
2024-08-04 CVE Updated
2024-08-04 First Exploit
2025-03-30 EPSS Updated
---------- Exploited in Wild
---------- KEV Due Date

CWE

CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer
CWE-125: Out-of-bounds Read

CAPEC

References (7)

URL	Tag	Source
https://github.com/google/oss-fuzz-vulns/blob/main/vulns/selinux/OSV-2021-585.yaml	Third Party Advisory
https://lore.kernel.org/selinux/CAEN2sdqJKHvDzPnxS-J8grU8fSf32DDtx=kyh84OsCq_Vm+yaQ%40mail.gmail.com/T	X_refsource_misc

URL	Date	SRC
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=32675	2024-08-04

URL	Date	SRC
https://github.com/SELinuxProject/selinux/commit/340f0eb7f3673e8aacaf0a96cbfcd4d12a405521	2023-11-07

URL	Date	SRC
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/U7ZYR3PIJ75N6U2IONJWCKZ5L2NKJTGR	2023-11-07
https://access.redhat.com/security/cve/CVE-2021-36087	2021-11-09
https://bugzilla.redhat.com/show_bug.cgi?id=1979668	2021-11-09

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Selinux Project Search vendor "Selinux Project"		Selinux Search vendor "Selinux Project" for product "Selinux"				3.2 Search vendor "Selinux Project" for product "Selinux" and version "3.2"		-		Affected
Fedoraproject Search vendor "Fedoraproject"		Fedora Search vendor "Fedoraproject" for product "Fedora"				35 Search vendor "Fedoraproject" for product "Fedora" and version "35"		-		Affected