Log in Start free

Vulnerability · Published May 26, 2021 · Assigned by redhat

CVE-2021-3527

Medium 5.5

In plain English

A medium-severity resource allocation without limits in QEMU. 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 32% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)5.5Medium
Exploit odds (30 days)0.4%top 68.5% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

Official description

A flaw was found in the USB redirector device (usb-redir) of QEMU. Small USB packets are combined into a single, large transfer request, to reduce the overhead and improve performance. The combined size of the bulk transfer is used to dynamically allocate a variable length array (VLA) on the stack without proper validation. Since the total size is not bounded, a malicious guest could use this flaw to influence the array length and cause the QEMU process to perform an excessive allocation on the stack, resulting in a denial of service.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Alpine:v3.20qemu6.0.0-r2ALPINE-CVE-2021-3527
Alpine:v3.21qemu6.0.0-r2ALPINE-CVE-2021-3527
Alpine:v3.22qemu6.0.0-r2ALPINE-CVE-2021-3527
Alpine:v3.23qemu6.0.0-r2ALPINE-CVE-2021-3527
Alpine:v3.24qemu6.0.0-r2ALPINE-CVE-2021-3527
Debian:12qemu1:5.2+dfsg-11DEBIAN-CVE-2021-3527
Debian:13qemu1:5.2+dfsg-11DEBIAN-CVE-2021-3527
Debian:14qemu1:5.2+dfsg-11DEBIAN-CVE-2021-3527
Ubuntu:22.04:LTSqemu1:6.0+dfsg-2expubuntu1UBUNTU-CVE-2021-3527

Affected products (as reported)

VendorProductVersions
n/a QEMU all versions

Weakness: CWE-770

References