Vulnerability Description
An issue was discovered in Xen through 4.14.x. An x86 PV guest can trigger a host OS crash when handling guest access to MSR_MISC_ENABLE. When a guest accesses certain Model Specific Registers, Xen first reads the value from hardware to use as the basis for auditing the guest access. For the MISC_ENABLE MSR, which is an Intel specific MSR, this MSR read is performed without error handling for a #GP fault, which is the consequence of trying to read this MSR on non-Intel hardware. A buggy or malicious PV guest administrator can crash Xen, resulting in a host Denial of Service. Only x86 systems are vulnerable. ARM systems are not vulnerable. Only Xen versions 4.11 and onwards are vulnerable. 4.10 and earlier are not vulnerable. Only x86 systems that do not implement the MISC_ENABLE MSR (0x1a0) are vulnerable. AMD and Hygon systems do not implement this MSR and are vulnerable. Intel systems do implement this MSR and are not vulnerable. Other manufacturers have not been checked. Only x86 PV guests can exploit the vulnerability. x86 HVM/PVH guests cannot exploit the vulnerability.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Xen | Xen | >= 4.11.0, <= 4.14.0 |
| Fedoraproject | Fedora | 31 |
| Debian | Debian Linux | 10.0 |
| Opensuse | Leap | 15.2 |
Related Weaknesses (CWE)
References
- http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00008.htmlThird Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://security.gentoo.org/glsa/202011-06Third Party Advisory
- https://www.debian.org/security/2020/dsa-4769Third Party Advisory
- https://xenbits.xen.org/xsa/advisory-333.htmlPatchVendor Advisory
- http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00008.htmlThird Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://security.gentoo.org/glsa/202011-06Third Party Advisory
- https://www.debian.org/security/2020/dsa-4769Third Party Advisory
- https://xenbits.xen.org/xsa/advisory-333.htmlPatchVendor Advisory
FAQ
What is CVE-2020-25602?
CVE-2020-25602 is a vulnerability with a CVSS score of 6.0 (MEDIUM). An issue was discovered in Xen through 4.14.x. An x86 PV guest can trigger a host OS crash when handling guest access to MSR_MISC_ENABLE. When a guest accesses certain Model Specific Registers, Xen fi...
How severe is CVE-2020-25602?
CVE-2020-25602 has been rated MEDIUM with a CVSS base score of 6.0/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2020-25602?
Check the references section above for vendor advisories and patch information. Affected products include: Xen Xen, Fedoraproject Fedora, Debian Debian Linux, Opensuse Leap.