Critical Vulnerability in Xen Package: Multiple NULL Pointer Dereferences
Summary
ALPINE-CVE-2025-27466: [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 th... Affects xen versions < 4.18.5-r2. Fixed in 4.18.5-r2. How to fix ↓
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Background
The Xen package is a powerful open-source hypervisor that allows multiple operating systems to run concurrently on a single physical machine. It is widely used in cloud computing and virtualization environments due to its efficiency and flexibility. However, the Xen package has recently been identified to have vulnerabilities related to the handling of guest memory pages, which could lead to significant security risks if not addressed promptly.
Vulnerability Detail
The vulnerabilities stem from multiple NULL pointer dereferences in the viridian code of the Xen package. Specifically, these issues include a NULL pointer dereference during the updating of the reference TSC area (CVE-2025-27466), another NULL pointer dereference when assuming the SIM page is mapped for synthetic timer message delivery (CVE-2025-58142), and a race condition that allows a guest to free a page while it is still present in the guest physical to machine (p2m) page tables (CVE-2025-58143). These vulnerabilities can lead to system crashes, data corruption, or unauthorized access to sensitive information.
How To Fix
Minimum fixed version
4.18.5-r2
This is the first release that contains the fix.
sudo apk add --upgrade xenTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary workaround, consider disabling features that rely on the affected functionalities until the package can be updated. However, this may limit certain capabilities of the Xen hypervisor.
Conclusion
The Xen package has critical vulnerabilities that need immediate attention. By updating to the patched versions, users can protect their systems from potential exploits. Utilizing tools like Vulert can help in monitoring and managing open-source vulnerabilities effectively.
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FAQ
The vulnerabilities can lead to system crashes, data corruption, or unauthorized access to sensitive information, posing significant security risks.
You can use Vulert, which monitors and alerts for open-source vulnerabilities in your software. Simply upload your manifest file like package-lock.json to check for vulnerabilities.
The affected versions include Xen in Alpine Linux v3.19, v3.20, v3.21, and v3.22 prior to their respective patched versions.
Yes, you can disable features that rely on the affected functionalities as a temporary workaround.
Detailed information can be found in the official CVE records and the Alpine Linux security advisories.
References
Related vulnerabilities
Recent vulnerabilities recorded for xen.
