SB2025090955 - Citrix XenServer update for Xen

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Main Vulnerability Database SB2025090955

SB2025090955 - Citrix XenServer update for Xen

Published: September 9, 2025

Security Bulletin ID SB2025090955
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 4
Exploitation vector Local access
Highest impact Code execution

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 4 vulnerabilities.


1) NULL pointer dereference (CVE-ID: CVE-2025-27466)

CWE-ID: CWE-476 - NULL Pointer Dereference

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:H/E:U/U:Green


The vulnerability allows a malicious guest to perform a denial of service (DoS) attack.

The vulnerability exists due to a NULL pointer dereference error when updating the reference TSC area. A malicious guest can perform a denial of service (DoS) attack against the hypervisor.



2) NULL pointer dereference (CVE-ID: CVE-2025-58142)

CWE-ID: CWE-476 - NULL Pointer Dereference

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:H/E:U/U:Green


The vulnerability allows a malicious guest to perform a denial of service (DoS) attack.

The vulnerability exists due to a NULL pointer dereference error by assuming the SIM page is mapped when a synthetic timer message has to be delivered. A malicious guest can perform a denial of service (DoS) attack against the hypervisor.


3) Race condition (CVE-ID: CVE-2025-58143)

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H/E:U/U:Green


The vulnerability allows a malicious guest to compromise the hypervisor.

The vulnerability exists due to a race condition in the mapping of the reference TSC page. A malicious guest can exploit the race and gain unauthorized access to sensitive information and escalate privileges on the system.


4) Input validation error (CVE-ID: CVE-2025-58146)

CWE-ID: CWE-20 - Improper input validation

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:H/E:U/U:Green


The vulnerability allows a malicious guest to perform a denial of service (DoS) attack.

The vulnerability exists due to insufficient validation of XAPI UTF-8 string. A malicious guest can pass specially crafted input to the application and perform a denial of service (DoS) attack.


Remediation

Install update from vendor's website.

References