VDB-207075 · CVE-2021-23177 · Issue 1565

libarchive Access Control List access control

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.
6.9	$0-$5k	0.00

Summaryinfo

A vulnerability, which was classified as critical, has been found in libarchive. Affected by this vulnerability is an unknown functionality of the component Access Control List Handler. Performing a manipulation results in access control. This vulnerability is known as CVE-2021-23177. Remote exploitation of the attack is possible. No exploit is available. To fix this issue, it is recommended to deploy a patch.

Detailsinfo

A vulnerability, which was classified as critical, was found in libarchive (File Compression Software) (affected version unknown). This affects an unknown functionality of the component Access Control List Handler. The manipulation with an unknown input leads to a access control vulnerability. CWE is classifying the issue as CWE-284. The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

An improper link resolution flaw while extracting an archive can lead to changing the access control list (ACL) of the target of the link. An attacker may provide a malicious archive to a victim user, who would trigger this flaw when trying to extract the archive. A local attacker may use this flaw to change the ACL of a file on the system and gain more privileges.

The weakness was published 08/24/2022 as 1565. It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2021-23177 since 12/16/2021. It demands that the victim is doing some kind of user interaction. The technical details are unknown and an exploit is not publicly available. The attack technique deployed by this issue is T1068 according to MITRE ATT&CK.

The vulnerability scanner Nessus provides a plugin with the ID 239805 (TencentOS Server 3: libarchive (TSSA-2022:0019)), which helps to determine the existence of the flaw in a target environment.

Applying the patch fba4f123cc456d2b2538f811bb831483bf336bad 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 (239805). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

File Compression Software

Name

libarchive

License

open-source

Website

Product: https://github.com/libarchive/libarchive/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.0
VulDB Meta Temp Score: 6.9

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.8
NVD Vector: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

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

Exploitinginfo

Class: Access control
CWE: CWE-284 / CWE-266
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Nessus ID: 239805
Nessus Name: TencentOS Server 3: libarchive (TSSA-2022:0019)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔍

Patch: fba4f123cc456d2b2538f811bb831483bf336bad

Timelineinfo

12/16/2021 🔍
08/24/2022 +250 days 🔍
08/24/2022 +0 days 🔍
06/20/2025 +1031 days 🔍

Sourcesinfo

Product: github.com

Advisory: 1565
Status: Confirmed

CVE: CVE-2021-23177 (🔍)
GCVE (CVE): GCVE-0-2021-23177
GCVE (VulDB): GCVE-100-207075

Entryinfo

Created: 08/24/2022 09:37
Updated: 06/20/2025 04:36
Changes: 08/24/2022 09:37 (41), 09/25/2022 10:06 (11), 06/20/2025 04:36 (16)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.