SB2025120853 - Multiple vulnerabilities in Citrix XenServer

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Main Vulnerability Database SB2025120853

SB2025120853 - Multiple vulnerabilities in Citrix XenServer

Published: December 8, 2025

Security Bulletin ID SB2025120853
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 2
Exploitation vector Local access
Highest impact Data manipulation

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 2 vulnerabilities.


1) Insufficient Entropy (CVE-ID: CVE-2025-62626)

CWE-ID: CWE-331 - Insufficient Entropy

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


The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to insufficient entropy in Zen 5 processors, which causes the RDSEED instruction to return 0 at a rate inconsistent with randomness while incorrectly signaling success (CF=1), indicating a potential misclassification of failure as success. A local user can escalate privileges on the system.


2) Improper Verification of Cryptographic Signature (CVE-ID: CVE-2024-36347)

CWE-ID: CWE-347 - Improper Verification of Cryptographic Signature

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


The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to improper signature verification of x86 instruction execution. A local privileged user can load malicious microcode and execute it on the system.


Remediation

Install update from vendor's website.

References