DEBIAN-CVE-2020-25603
- Source
- https://security-tracker.debian.org/tracker/CVE-2020-25603
- Import Source
- https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2020-25603.json
- JSON Data
- https://api.test.osv.dev/v1/vulns/DEBIAN-CVE-2020-25603
- Upstream
- Published
- 2020-09-23T22:15:13Z
- Modified
- 2025-09-25T22:40:37Z
- Severity
-
- 7.8 (High) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
- Summary
- [none]
- Details
-
An issue was discovered in Xen through 4.14.x. There are missing memory barriers when accessing/allocating an event channel. Event channels control structures can be accessed lockless as long as the port is considered to be valid. Such a sequence is missing an appropriate memory barrier (e.g., smp_*mb()) to prevent both the compiler and CPU from re-ordering access. A malicious guest may be able to cause a hypervisor crash resulting in a Denial of Service (DoS). Information leak and privilege escalation cannot be excluded. Systems running all versions of Xen are affected. Whether a system is vulnerable will depend on the CPU and compiler used to build Xen. For all systems, the presence and the scope of the vulnerability depend on the precise re-ordering performed by the compiler used to build Xen. We have not been able to survey compilers; consequently we cannot say which compiler(s) might produce vulnerable code (with which code generation options). GCC documentation clearly suggests that re-ordering is possible. Arm systems will also be vulnerable if the CPU is able to re-order memory access. Please consult your CPU vendor. x86 systems are only vulnerable if a compiler performs re-ordering.
- References
Affected packages
Debian:11 / xen
Package
- Name
- xen
- Purl
- pkg:deb/debian/xen?arch=source
Debian:12 / xen
Package
- Name
- xen
- Purl
- pkg:deb/debian/xen?arch=source
Debian:13 / xen
Package
- Name
- xen
- Purl
- pkg:deb/debian/xen?arch=source
Debian:14 / xen
Package
- Name
- xen
- Purl
- pkg:deb/debian/xen?arch=source