CVE-2021-41773

Critical · CVSS 9.8EPSS 100.0%CISA KEVCWE-22 · Path Traversal

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

A flaw was found in a change made to path normalization in Apache HTTP Server 2.4.49. An attacker could use a path traversal attack to map URLs to files outside the directories configured by Alias-like directives. If files outside of these directories are not protected by the usual default configuration "require all denied", these requests can succeed. If CGI scripts are also enabled for these aliased pathes, this could allow for remote code execution. This issue is known to be exploited in the wild. This issue only affects Apache 2.4.49 and not earlier versions. The fix in Apache HTTP Server 2.4.50 was found to be incomplete, see CVE-2021-42013.

References

NVD MITRE CVE.org CISA KEV

Published Oct 5, 2021

Community ground truth

Community verdict

2 verdicts

Not a real issue

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Community real-world severity: Critical (Critical 2) — CVSS base score 9.8

In line with its CVSS base score.

Field notes & remediation

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0
Field note · Diego RamírezCurated
Confirmed exploited in the wild — listed in the CISA KEV catalog (added 2021-11-03). Linked to known ransomware campaigns. Treat as real and prioritize patching over triage.