Vulnerability · Published Dec 15, 2020 · Assigned by mitre

CVE-2020-29569

High 8.8

In plain English

A high-severity security flaw in the linux-lts 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 34% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)8.8High
Exploit odds (30 days)0.4%top 66.0% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

Official description

An issue was discovered in the Linux kernel through 5.10.1, as used with Xen through 4.14.x. The Linux kernel PV block backend expects the kernel thread handler to reset ring->xenblkd to NULL when stopped. However, the handler may not have time to run if the frontend quickly toggles between the states connect and disconnect. As a consequence, the block backend may re-use a pointer after it was freed. A misbehaving guest can trigger a dom0 crash by continuously connecting / disconnecting a block frontend. Privilege escalation and information leaks cannot be ruled out. This only affects systems with a Linux blkback.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Alpine:v3.20linux-lts5.10.4-r0ALPINE-CVE-2020-29569
Alpine:v3.21linux-lts5.10.4-r0ALPINE-CVE-2020-29569
Alpine:v3.22linux-lts5.10.4-r0ALPINE-CVE-2020-29569
Alpine:v3.23linux-lts5.10.4-r0ALPINE-CVE-2020-29569
Debian:12linux5.9.15-1DEBIAN-CVE-2020-29569
Debian:13linux5.9.15-1DEBIAN-CVE-2020-29569
Debian:14linux5.9.15-1DEBIAN-CVE-2020-29569
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2020-29569
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2020-29569
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2020-29569

Affected products (as reported)

VendorProductVersions
n/a n/a n/a

References