CVE-2021-20181

qemu: 9pfs: TOCTOU privilege escalation vulnerability

Published May 13, 2021 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed
Description
A race condition flaw was found in the 9pfs server implementation of QEMU up to and including 5.2.0. This flaw allows a malicious 9p client to cause a use-after-free error, potentially escalating their privileges on the system. The highest threat from this vulnerability is to confidentiality, integrity as well as system availability.

Analysis

No analysis available yet

Remediation

No remediation available yet

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-2560-1 qemu security update
Debian DLA Debian DLA DLA-3099-1 qemu security update
EUVD EUVD EUVD-2021-7636 A race condition flaw was found in the 9pfs server implementation of QEMU up to and including 5.2.0. This flaw allows a malicious 9p client to cause a use-after-free error, potentially escalating their privileges on the system. The highest threat from this vulnerability is to confidentiality, integrity as well as system availability.
Ubuntu USN Ubuntu USN USN-4725-1 QEMU vulnerabilities
Ubuntu USN Ubuntu USN USN-8412-1 QEMU vulnerabilities
History

No history.

Weaknesses
  • CWE-362

    Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

  • CWE-367

    Time-of-check Time-of-use (TOCTOU) Race Condition

  • CWE-416

    Use After Free

Sources

Status
PUBLISHED
Assigner
redhat
Published
Updated
Aug 3, 2024, 5:30 PM
Reserved
Dec 17, 2020, 12:00 AM
Status
Modified
Published
May 13, 2021, 4:15 PM
Modified
Jun 17, 2026, 3:33 AM
Severity
Moderate
Public date
Jan 14, 2021, 12:00 AM