Buffer overflow in Apache Http_server

CVE-2021-39275

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 earlie…

Vulnerability class: Buffer Overflow

EPSS: 0.363 (98.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-39275?
CVE-2021-39275 is a critical-severity vulnerability in Apache Http_server, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2021-09-16.
How severe is CVE-2021-39275?
Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2021-39275 known to be exploited?
17 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.