Vulnetix
Try Vulnetix Request Demo
CVE-2020-25601 PUBLISHED

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.

EPSS 0.08% · 22.6th percentile

Risk Scores

EPSS Score
0.08%
22.6th percentile

Affected Products

VendorProductVersions
Ubuntu:20.04:LTSxen4.11.3+24-g14b62ab3e5-1ubuntu2.2, 4.9.2-0ubuntu6, 4.9.2-0ubuntu7
Ubuntu:18.04:LTSxen4.9.0-0ubuntu3, 4.9.0-0ubuntu4, 4.9.2-0ubuntu1
Ubuntu:16.04:LTSxen4.6.5-0ubuntu1.2, 0, 4.6.5-0ubuntu1.4

Timeline

References

Open in Interactive Console →