PT-2025-9009 · Linux+1 · Linux Kernel+1

Published 2025-02-27 · Updated 2025-02-28 · CVE-2025-21818

Positive Technologies (AI Summary)

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description A vulnerability in the Linux kernel has been identified, specifically in the xen hypercall hvm() function used when running as a Xen PVH guest. This function clobbers the %rbx register, which may cause an early system crash if the caller relies on %rbx being preserved. The issue can be mitigated by using a saved register instead of %rbx.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Related Identifiers

CVE-2025-21818

Affected Products

Debian

Linux Kernel

References · 17

• https://security-tracker.debian.org/tracker/source-package/linux · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2025-21818 · Vendor Advisory
• https://ubuntu.com/security/CVE-2025-21818 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2025-21818 · Vendor Advisory
• http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2025-21818 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2025-21818 · Security Note
• https://cve.org/CVERecord?id=CVE-2025-21818 · Security Note
• https://osv.dev/vulnerability/UBUNTU-CVE-2025-21818 · Vendor Advisory
• https://git.kernel.org/stable/c/522d726824cc570e0b6bf0b3af4d5a826f1b17c5 · Note
• https://git.kernel.org/linus/98a5cfd2320966f40fe049a9855f8787f0126825 · Note
• https://git.kernel.org/stable/c/4890a0858c09d96f3234a8f94663de80a7201bc4 · Note
• https://git.kernel.org/stable/c/23f6f420cd727d641f95478fcf3bbbee41e4e5d6 · Note
• https://git.kernel.org/stable/c/242f7584da3ad041a9db809d33d27a8be8eccc29 · Note
• https://git.kernel.org/stable/c/98a5cfd2320966f40fe049a9855f8787f0126825 · Note
• https://twitter.com/CVEnew/status/1895241148039651662 · Twitter Post