SELinux 3.2 CIL Compiler __cil_verify_classperms use after free

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
4.3$0-$5k0.00

Summaryinfo

A vulnerability was found in SELinux 3.2. It has been classified as critical. Affected is the function __cil_verify_classperms of the component CIL Compiler. This manipulation causes use after free. This vulnerability is tracked as CVE-2021-36084. No exploit exists. It is recommended to apply a patch to fix this issue.

Detailsinfo

A vulnerability was found in SELinux 3.2. It has been declared as critical. Affected by this vulnerability is the function __cil_verify_classperms of the component CIL Compiler. The manipulation with an unknown input leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. As an impact it is known to affect confidentiality, integrity, and availability.

The weakness was disclosed 07/01/2021. It is possible to read the advisory at bugs.chromium.org. This vulnerability is known as CVE-2021-36084. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 209513 (Debian dla-3930 : libsepol1 - security update), which helps to determine the existence of the flaw in a target environment.

Applying a patch is able to eliminate this problem. The bugfix is ready for download at github.com.

The vulnerability is also documented in the vulnerability database at Tenable (209513). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.4
VulDB Meta Temp Score: 4.3

VulDB Base Score: 5.5
VulDB Temp Score: 5.3
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 3.3
NVD Vector: 🔍

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Nessus ID: 209513
Nessus Name: Debian dla-3930 : libsepol1 - security update

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔍

Patch: github.com

Timelineinfo

07/01/2021 🔍
07/01/2021 +0 days 🔍
07/01/2021 +0 days 🔍
11/04/2025 +1587 days 🔍

Sourcesinfo

Advisory: bugs.chromium.org
Status: Confirmed

CVE: CVE-2021-36084 (🔍)
GCVE (CVE): GCVE-0-2021-36084
GCVE (VulDB): GCVE-100-177847
scip Labs: https://www.scip.ch/en/?labs.20140109

Entryinfo

Created: 07/01/2021 07:39
Updated: 11/04/2025 05:42
Changes: 07/01/2021 07:39 (38), 07/04/2021 16:19 (5), 10/22/2024 15:04 (16), 11/04/2025 05:42 (19)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Want to stay up to date on a daily basis?

Enable the mail alert feature now!