Vulnerability · Published Dec 15, 2020 · Assigned by mitre
CVE-2020-29571
Medium 6.2
In plain English
A medium-severity security flaw in the xen package (Alpine). There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 33% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.20 | xen | 4.14.1-r0 | ALPINE-CVE-2020-29571 |
| Alpine:v3.21 | xen | 4.14.1-r0 | ALPINE-CVE-2020-29571 |
| Alpine:v3.22 | xen | 4.14.1-r0 | ALPINE-CVE-2020-29571 |
| Alpine:v3.23 | xen | 4.14.1-r0 | ALPINE-CVE-2020-29571 |
| Alpine:v3.24 | xen | 4.14.1-r0 | ALPINE-CVE-2020-29571 |
| Debian:12 | xen | 4.14.0+88-g1d1d1f5391-1 | DEBIAN-CVE-2020-29571 |
| Debian:13 | xen | 4.14.0+88-g1d1d1f5391-1 | DEBIAN-CVE-2020-29571 |
| Debian:14 | xen | 4.14.0+88-g1d1d1f5391-1 | DEBIAN-CVE-2020-29571 |
Affected products (as reported)
References
- https://xenbits.xenproject.org/xsa/advisory-359.html x_refsource_MISC
- DSA-4812 vendor-advisory, x_refsource_DEBIAN
- FEDORA-2020-64859a826b vendor-advisory, x_refsource_FEDORA
- FEDORA-2020-df772b417b vendor-advisory, x_refsource_FEDORA
- GLSA-202107-30 vendor-advisory, x_refsource_GENTOO