Vulnerability Monitor

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CVE-2020-25601

An issue was discovered in Xen through 4.14.x. There is a lack of preemption in evtchn_reset() / evtchn_destroy(). In particular, the FIFO event channel model allows guests to have a large number of event channels active at a time. Closing all of these (when resetting all event channels or when cleaning up after the guest) may take extended periods of time. So far, there was no arrangement for preemption at suitable intervals, allowing a CPU to spend an almost unbounded amount of time in the processing of these operations. Malicious or buggy guest kernels can mount a Denial of Service (DoS) attack affecting the entire system. All Xen versions are vulnerable in principle. Whether versions 4.3 and older are vulnerable depends on underlying hardware characteristics.

Published

2020-09-23T22:15:13.713

Last Modified

2024-11-21T05:18:12.487

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 5.5 (MEDIUM)

CVSSv2 Vector

AV:L/AC:L/Au:N/C:N/I:N/A:C

  • Access Vector: LOCAL
  • Access Complexity: LOW
  • Authentication: NONE
  • Confidentiality Impact: NONE
  • Integrity Impact: NONE
  • Availability Impact: COMPLETE
Exploitability Score

3.9

Impact Score

6.9

Weaknesses
  • Type: Primary
    NVD-CWE-noinfo
Affected Vendors & Products
Type Vendor Product Version/Range Vulnerable?
Operating System xen xen ≤ 4.14.0 Yes
Operating System debian debian_linux 10.0 Yes
Operating System fedoraproject fedora 31 Yes
Operating System fedoraproject fedora 32 Yes
Operating System fedoraproject fedora 33 Yes
Operating System opensuse leap 15.2 Yes
References