VDB-175348 · CVE-2021-3518 · Nessus 236735

libxml2 up to 2.9.10 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.
6.0	$0-$5k	0.00

Summaryinfo

A vulnerability described as critical has been identified in libxml2 up to 2.9.10. This affects an unknown function. Executing a manipulation can lead to use after free. This vulnerability appears as CVE-2021-3518. The attack may be performed from remote. There is no available exploit. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability classified as critical was found in libxml2 up to 2.9.10 (Document Processing Software). This vulnerability affects an unknown code block. 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 presented 05/19/2021. The advisory is shared for download at bugzilla.redhat.com. This vulnerability was named CVE-2021-3518. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 236735 (Alibaba Cloud Linux 3 : 0047: libxml2 (ALINUX3-SA-2021:0047)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 2.9.11 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (236735). Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

Document Processing Software

Name

libxml2

Version

License

open-source

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.3
VulDB Meta Temp Score: 6.0

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

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

Physical: No
Local: No
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: 236735
Nessus Name: Alibaba Cloud Linux 3 : 0047: libxml2 (ALINUX3-SA-2021:0047)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: libxml2 2.9.11

Timelineinfo

04/27/2021 🔍
05/19/2021 +22 days 🔍
05/19/2021 +0 days 🔍
05/16/2025 +1458 days 🔍

Sourcesinfo

Advisory: bugzilla.redhat.com
Status: Confirmed

CVE: CVE-2021-3518 (🔍)
GCVE (CVE): GCVE-0-2021-3518
GCVE (VulDB): GCVE-100-175348

Entryinfo

Created: 05/19/2021 07:59
Updated: 05/16/2025 05:04
Changes: 05/19/2021 07:59 (37), 05/22/2021 13:39 (5), 05/16/2025 05:04 (16)
Complete: 🔍
Cache ID: 216::103