Cyber Resilience

CVE-2021-39275

Critical

Published: 16 September 2021

Published
16 September 2021
Modified
01 May 2025
KEV Added
—
Patch
—
CVSS Score v3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.3367 97.1th percentile
Risk Priority 40 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-39275 is a critical-severity Out-of-bounds Write (CWE-787) vulnerability in Debian Debian Linux. Its CVSS base score is 9.8 (Critical).

Operationally, ranked in the top 2.9% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

ap_escape_quotes() may write beyond the end of a buffer when given malicious input. No included modules pass untrusted data to these functions, but third-party / external modules may. This issue affects Apache HTTP Server 2.4.48 and earlier.

CWE(s)
CWE-787

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

apache
http server
≤ 2.4.49
fedoraproject
fedora
34, 35
debian
debian linux
10.0, 11.0, 9.0
netapp
cloud backup
all versions
netapp
clustered data ontap
all versions
netapp
storagegrid
all versions
oracle
http server
12.2.1.3.0, 12.2.1.4.0
oracle
instantis enterprisetrack
17.1, 17.2, 17.3
oracle
zfs storage appliance kit
8.8
siemens
sinec nms
all versions
+1 more product configuration(s) — see NVD for full list

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

SI-16 Memory Protection
addresses: CWE-787

Out-of-bounds writes that corrupt control flow or inject shellcode are rendered non-executable by the same memory protections.

References