Memory Leak Affecting xen package, versions <4.14.0+80-gd101b417b7-1


Severity

Recommended
0.0
high
0
10

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Threat Intelligence

EPSS
0.05% (16th percentile)

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  • Snyk IDSNYK-DEBIAN11-XEN-1011880
  • published23 Sept 2020
  • disclosed23 Sept 2020

Introduced: 23 Sep 2020

CVE-2020-25603  (opens in a new tab)
CWE-401  (opens in a new tab)

How to fix?

Upgrade Debian:11 xen to version 4.14.0+80-gd101b417b7-1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream xen package and not the xen package as distributed by Debian. See How to fix? for Debian:11 relevant fixed versions and status.

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.

CVSS Scores

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