Vulnerability in Qemu
CVE-2021-20181
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.
Vulnerability class: TOCTOU (Time-of-Check to Time-of-Use)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.003 (24.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 24th percentile — 24.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: +0.000
Affected products
- Qemu
- Debian Linux — versions 9.0, 10.0
- Qemu — versions up to, including 5.2.0
Weakness classification (CWE)
References
- www.zerodayinitiative.com/advisories/ZDI-21-159/ (VDB Entry, Third Party Advisory)
- lists.debian.org/debian-lts-announce/2021/02/msg00024.html (mailing-list, Mailing List, Third Party Advisory)
- bugzilla.redhat.com/show_bug.cgi (Patch, Third Party Advisory, Issue Tracking)
- security.netapp.com/advisory/ntap-20210720-0009/ (Third Party Advisory)
- lists.debian.org/debian-lts-announce/2022/09/msg00008.html (mailing-list, Mailing List, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-20181?
- CVE-2021-20181 is a high-severity vulnerability in Qemu, classified under Time-of-check Time-of-use (TOCTOU) Race Condition. CVSS score: 7.5/10. Published 2021-05-13.
- How severe is CVE-2021-20181?
- High severity. CVSS v3 base score is 7.5 out of 10.