Xen 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 (≈)
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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.
4.1$0-$5k0.00

Summaryinfo

A vulnerability marked as critical has been reported in Xen. Affected by this vulnerability is an unknown functionality. This manipulation causes use after free. This vulnerability is tracked as CVE-2021-28691. The attack is possible to be carried out remotely. No exploit exists. It is recommended to apply a patch to fix this issue.

Detailsinfo

A vulnerability has been found in Xen (Virtualization Software) (the affected version is unknown) and classified as critical. Affected by this vulnerability is an unknown code. 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 availability.

The weakness was disclosed 06/29/2021. It is possible to read the advisory at xenbits.xenproject.org. This vulnerability is known as CVE-2021-28691. The technical details are unknown and an exploit is not publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 246652 (Linux Distros Unpatched Vulnerability : CVE-2021-47111), which helps to determine the existence of the flaw in a target environment.

Applying a patch is able to eliminate this problem.

The vulnerability is also documented in the vulnerability database at Tenable (246652). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

Name

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.3
VulDB Meta Temp Score: 4.1

VulDB Base Score: 4.3
VulDB Temp Score: 4.1
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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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: 🔍

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Nessus ID: 246652
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2021-47111

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔍

Timelineinfo

03/18/2021 🔍
06/29/2021 +102 days 🔍
06/29/2021 +0 days 🔍
08/09/2025 +1502 days 🔍

Sourcesinfo

Advisory: xenbits.xenproject.org
Status: Confirmed

CVE: CVE-2021-28691 (🔍)
GCVE (CVE): GCVE-0-2021-28691
GCVE (VulDB): GCVE-100-177727

Entryinfo

Created: 06/29/2021 21:35
Updated: 08/09/2025 17:59
Changes: 06/29/2021 21:35 (35), 07/03/2021 14:58 (5), 08/09/2025 17:59 (16)
Complete: 🔍
Cache ID: 216::103

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

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