HOMEVULNERABILITIESCVE-2020-35504
MEDIUM

CVE-2020-35504

CWE-476Published: May 28, 2021· Updated: Jun 17, 2026

6.0
CVSS v3.1

Official Description

A NULL pointer dereference flaw was found in the SCSI emulation support of QEMU in versions before 6.0.0. 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.

NVD Source

Technical Analysis

CVE-2020-35504 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

Exploitability
Attack VectorLocal
Attack ComplexityLow
Privileges Req.High
User InteractionNone
ScopeChanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H

Affected Vendors & Products

Debian1 product(s)
debian linux
Fedora1 product(s)
fedora
qemu1 product(s)
qemu
Source: NVD CPE · 3 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

All References (12)

http://www.openwall.com/lists/oss-security/2021/04/16/3Mailing List · Patch · Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1909766Issue Tracking · Patch · Third Party Advisory
https://www.openwall.com/lists/oss-security/2021/04/16/3Mailing List · Patch · Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/04/16/3Mailing List · Patch · Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1909766Issue Tracking · Patch · Third Party Advisory
https://www.openwall.com/lists/oss-security/2021/04/16/3Mailing List · Patch · Third Party Advisory

Quick Facts

CVE IDCVE-2020-35504
CVSS Score6.0 / 10
SeverityMEDIUM
WeaknessCWE-476
CISA KEVNo
Affected3 vendor(s)
PublishedMay 28, 2021

Related CVEs (CWE-476)

Recommended Actions

  • Apply vendor patches immediately
  • Monitor CVE-2020-35504 in threat intel feeds
  • Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.