Xen Reference TSC Area null pointer dereference

CVSS Meta Temp Score
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CTI Interest Score
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5.5$0-$5k0.00

Summaryinfo

A vulnerability was found in Xen. It has been classified as critical. This vulnerability affects unknown code of the component Reference TSC Area. Performing a manipulation results in null pointer dereference. This vulnerability is identified as CVE-2025-27466. There is not any exploit available. It is suggested to install a patch to address this issue.

Detailsinfo

A vulnerability was found in Xen (unknown version). It has been classified as critical. This affects an unknown code block of the component Reference TSC Area. The manipulation with an unknown input leads to a null pointer dereference vulnerability. CWE is classifying the issue as CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. This is going to have an impact on availability. The summary by CVE is:

[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] There are multiple issues related to the handling and accessing of guest memory pages in the viridian code: 1. A NULL pointer dereference in the updating of the reference TSC area. This is CVE-2025-27466. 2. A NULL pointer dereference by assuming the SIM page is mapped when a synthetic timer message has to be delivered. This is CVE-2025-58142. 3. A race in the mapping of the reference TSC page, where a guest can get Xen to free a page while still present in the guest physical to machine (p2m) page tables. This is CVE-2025-58143.

The advisory is shared at xenbits.xen.org. This vulnerability is uniquely identified as CVE-2025-27466. Neither technical details nor an exploit are publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 264553 (Citrix XenServer Multiple Vulnerabilities (XSA-472)), 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 xenbits.xen.org.

The vulnerability is also documented in the databases at Tenable (264553), EUVD (EUVD-2025-28913) and CERT Bund (WID-SEC-2025-2007). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

  • Debian Linux
  • Fedora Linux
  • SUSE Linux
  • SUSE openSUSE
  • Open Source Xen

Productinfo

Type

Name

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.7
VulDB Meta Temp Score: 5.5

VulDB Base Score: 5.7
VulDB Temp Score: 5.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 264553
Nessus Name: Citrix XenServer Multiple Vulnerabilities (XSA-472)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔒

Patch: xenbits.xen.org

Timelineinfo

09/11/2025 Advisory disclosed
09/11/2025 +0 days VulDB entry created
01/07/2026 +118 days VulDB entry last update

Sourcesinfo

Advisory: xenbits.xen.org
Status: Confirmed

CVE: CVE-2025-27466 (🔒)
GCVE (CVE): GCVE-0-2025-27466
GCVE (VulDB): GCVE-100-323601
EUVD: 🔒
CERT Bund: WID-SEC-2025-2007 - Xen: Mehrere Schwachstellen

Entryinfo

Created: 09/11/2025 07:03
Updated: 01/07/2026 07:20
Changes: 09/11/2025 07:03 (51), 09/11/2025 16:53 (1), 09/11/2025 17:53 (1), 09/12/2025 09:13 (2), 01/07/2026 07:20 (7)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion

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