CVE-2020-35503
CWE-476Published: June 2, 2021· Updated: Jun 17, 2026
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.
Technical Analysis
CVE-2020-35503 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires high privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
A successful exploit results in availability disruption (denial of service), with a CVSS base score of 6.0.
The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (4)
Quick Facts
Related CVEs (CWE-476)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2020-35503 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts