NULL pointer dereference in Qemu
CVE-2021-4145
A NULL pointer dereference issue was found in the block mirror layer of QEMU in versions prior to 6.2.0. The `self` pointer is dereferenced in mirror_wait_on_conflicts() without ensuring that it's not NULL. A malicious unprivileged user within the guest could use this flaw to crash the QEMU process on the host when writing data reaches the threshold of mirroring node.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.004 (30.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 30th percentile — 30.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: -0.000
Affected products
- Qemu — versions 6.1.0
- Red Hat Enterprise Linux — versions 8.0
- Qemu — versions qemu-kvm 6.2.0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- bugzilla.redhat.com/show_bug.cgi (Patch, Third Party Advisory, Issue Tracking)
- gitlab.com/qemu-project/qemu/-/commit/66fed30c9cd11854fc878a4eceb507e915d7c9cd (Patch, Third Party Advisory)
- security.netapp.com/advisory/ntap-20220311-0004/ (Third Party Advisory)
- security.gentoo.org/glsa/202208-27 (vendor-advisory, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-4145?
- CVE-2021-4145 is a medium-severity vulnerability in Qemu, classified under NULL Pointer Dereference. CVSS score: 6.5/10. Published 2022-01-25.
- How severe is CVE-2021-4145?
- Medium severity. CVSS v3 base score is 6.5 out of 10.
- Is CVE-2021-4145 known to be exploited?
- 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.