6.5

CVE-2021-4145: qemu NULL Pointer Dereference

Modified
AliasesDEBIAN-CVE-2021-4145
Published 25-01-2022Last modified 03-08-2024

Vulnerability summary

CVE-2021-4145 is a medium (CVSS 6.5) NULL Pointer Dereference vulnerability in qemu. EPSS estimates a 0.39% chance of exploitation in the next 30 days, higher than 31.5% of scored vulnerabilities.

Overall risk
26/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.39%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 1
RHSA-2022:1759

Timeline

  1. 25-01-2022
    PublishedVulnerability first disclosed.
  2. 03-08-2024
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

3 scores · 2 sources · 2 versions

EPSS trend

Probability

0.39%

Chance of exploitation in the next 30 days

Percentile

32%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.39% on 22-09-2026

22-09-202622-10-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Debian1 product
  • qemu< 1:6.2+dfsg-1
Qemu1 product
  • qemu6.1.0 | 6.1.0:rc0 | 6.1.0:rc1 | 6.1.0:rc2 | 6.1.0:rc3 | 6.1.0:rc4
Redhat1 product

3 vendors · 3 products

References

6 links