CVE-2021-41773

Path traversal and file disclosure vulnerability in Apache HTTP Server 2.4.49

At a glance

Severity
HIGH 7.5
Exploitation
Known exploited (CISA KEV) · added 2021-11-03
Exploited per ENISA since 2021-11-03
EPSS
EPSS 99.99 % · percentile 100 (2026-10-27)
State
PUBLISHED
Published
Updated
Assigner
apache
NVD status
Analyzed

Description

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.

Scores

VersionScoreVectorScored by
CVSS 3.1HIGH 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:NCISA-ADP
CVSS 3.1CRITICAL 9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HNVD · nvd@nist.gov (Primary)
CVSS 3.1HIGH 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:NNVD · 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Secondary)
CVSS 2.0MEDIUM 4.3AV:N/AC:M/Au:N/C:P/I:N/A:NNVD · nvd@nist.gov (Primary)

Weaknesses (CWE)

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
Apache Software Foundation · Apache HTTP Serveraffected Apache HTTP Server 2.4 2.4.49

References

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
CISA Known Exploited VulnerabilitiesCC0 1.0
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD