Vulnerability · Published Sep 23, 2020 · Assigned by mitre
CVE-2020-25602
Medium 6.0
In plain English
A medium-severity security flaw in the xen package (Alpine). There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 26% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.20 | xen | 4.14.0-r1 | ALPINE-CVE-2020-25602 |
| Alpine:v3.21 | xen | 4.14.0-r1 | ALPINE-CVE-2020-25602 |
| Alpine:v3.22 | xen | 4.14.0-r1 | ALPINE-CVE-2020-25602 |
| Alpine:v3.23 | xen | 4.14.0-r1 | ALPINE-CVE-2020-25602 |
| Alpine:v3.24 | xen | 4.14.0-r1 | ALPINE-CVE-2020-25602 |
| Debian:12 | xen | 4.14.0+80-gd101b417b7-1 | DEBIAN-CVE-2020-25602 |
| Debian:13 | xen | 4.14.0+80-gd101b417b7-1 | DEBIAN-CVE-2020-25602 |
| Debian:14 | xen | 4.14.0+80-gd101b417b7-1 | DEBIAN-CVE-2020-25602 |
Affected products (as reported)
References
- https://xenbits.xen.org/xsa/advisory-333.html x_refsource_MISC
- FEDORA-2020-306b84fd07 vendor-advisory, x_refsource_FEDORA
- FEDORA-2020-f668e579be vendor-advisory, x_refsource_FEDORA
- DSA-4769 vendor-advisory, x_refsource_DEBIAN
- openSUSE-SU-2020:1608 vendor-advisory, x_refsource_SUSE
- FEDORA-2020-d46fe34349 vendor-advisory, x_refsource_FEDORA
- GLSA-202011-06 vendor-advisory, x_refsource_GENTOO