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Vulnerability · Published Feb 17, 2021 · Assigned by mitre

CVE-2021-26932

Medium 5.5

In plain English

A medium-severity security flaw in the linux package (Debian). There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 28% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)5.5Medium
Exploit odds (30 days)0.3%top 71.7% 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 3.2 through 5.10.16, as used by Xen. Grant mapping operations often occur in batch hypercalls, where a number of operations are done in a single hypercall, the success or failure of each one is reported to the backend driver, and the backend driver then loops over the results, performing follow-up actions based on the success or failure of each operation. Unfortunately, when running in PV mode, the Linux backend drivers mishandle this: Some errors are ignored, effectively implying their success from the success of related batch elements. In other cases, errors resulting from one batch element lead to further batch elements not being inspected, and hence successful ones to not be possible to properly unmap upon error recovery. Only systems with Linux backends running in PV mode are vulnerable. Linux backends run in HVM / PVH modes are not vulnerable. This affects arch/*/xen/p2m.c and drivers/xen/gntdev.c.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux5.10.19-1DEBIAN-CVE-2021-26932
Debian:13linux5.10.19-1DEBIAN-CVE-2021-26932
Debian:14linux5.10.19-1DEBIAN-CVE-2021-26932
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2021-26932
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2021-26932
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2021-26932

Affected products (as reported)

VendorProductVersions
n/a n/a n/a

References