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Vulnerability · Published Jun 2, 2021 · Assigned by redhat

CVE-2020-35503

Medium 6.0

In plain English

A medium-severity null pointer dereference in QEMU. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 20% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)6.0Medium
Exploit odds (30 days)0.3%top 80.1% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

Official description

A NULL pointer dereference flaw was found in the megasas-gen2 SCSI host bus adapter emulation of QEMU in versions before and including 6.0. This issue occurs in the megasas_command_cancelled() callback function while dropping a SCSI request. This flaw allows a privileged guest user to crash the QEMU process on the host, resulting in a denial of service. The highest threat from this vulnerability is to system availability.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Alpine:v3.20qemu6.1.0-r0ALPINE-CVE-2020-35503
Alpine:v3.21qemu6.1.0-r0ALPINE-CVE-2020-35503
Alpine:v3.22qemu6.1.0-r0ALPINE-CVE-2020-35503
Alpine:v3.23qemu6.1.0-r0ALPINE-CVE-2020-35503
Alpine:v3.24qemu6.1.0-r0ALPINE-CVE-2020-35503
Debian:12qemuno fix listedDEBIAN-CVE-2020-35503
Debian:13qemuno fix listedDEBIAN-CVE-2020-35503
Debian:14qemuno fix listedDEBIAN-CVE-2020-35503
Ubuntu:22.04:LTSqemuno fix listedUBUNTU-CVE-2020-35503
Ubuntu:24.04:LTSqemuno fix listedUBUNTU-CVE-2020-35503
Ubuntu:25.10qemuno fix listedUBUNTU-CVE-2020-35503
Ubuntu:26.04:LTSqemuno fix listedUBUNTU-CVE-2020-35503
Ubuntu:26.10qemuno fix listedUBUNTU-CVE-2020-35503
Ubuntu:26.04:LTSqemu-hweno fix listedUBUNTU-CVE-2020-35503
Ubuntu:26.10qemu-hweno fix listedUBUNTU-CVE-2020-35503

Affected products (as reported)

VendorProductVersions
n/a QEMU All QEMU versions before and including 6.0

Weakness: CWE-476

References