VDB

CVE-2020-29571

CVE-2020-29571 PUBLISHED

An issue was discovered in Xen through 4.14.x. A bounds check common to most operation time functions specific to FIFO event channels depends on the CPU observing consistent state. While the producer side uses appropriately ordered writes, the consumer side isn't protected against re-ordered reads, and may hence end up de-referencing a NULL pointer. Malicious or buggy guest kernels can mount a Denial of Service (DoS) attack affecting the entire system. Only Arm systems may be vulnerable. Whether a system is vulnerable depends on the specific CPU. x86 systems are not vulnerable.

EPSS 0.06% · 18.5th percentile

Risk Scores

EPSS Score
0.06%
18.5th percentile

Affected Products

VendorProductVersions
Ubuntu:16.04:LTSxen0, 4.5.1-0ubuntu1, 4.5.1-0ubuntu2
Ubuntu:18.04:LTSxen0, 4.9.0-0ubuntu4, 4.9.2-0ubuntu1
Ubuntu:20.04:LTSxen0, 4.9.2-0ubuntu2, 4.9.2-0ubuntu6

Timeline

  • Dec 15, 2020 CVE Published
  • Apr 14, 2021 EPSS Score
  • Jun 22, 2021 EPSS Score
  • Aug 24, 2021 EPSS Score
  • Oct 25, 2021 EPSS Score
  • Jan 6, 2022 EPSS Score
  • Feb 4, 2022 EPSS Score
  • Feb 27, 2022 EPSS Score
  • Apr 1, 2022 EPSS Score
  • May 1, 2022 EPSS Score
  • Jul 2, 2022 EPSS Score
  • Sep 4, 2022 EPSS Score
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