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.

Metrics

CVSS 3.1 9.8/10CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Weakness enumeration

CWE-22

Affected software

Vendor	Product	Versions
Apache Software Foundation	Apache HTTP Server	Apache HTTP Server 2.4 2.4.49

References

http://packetstormsecurity.com/files/164418/Apache-HTTP-Server-2.4.49-Path-Traversal-Remote-Code-Execution.htmlExploit, Third Party Advisory, VDB Entry
http://packetstormsecurity.com/files/164418/Apache-HTTP-Server-2.4.49-Path-Traversal.htmlExploit, Third Party Advisory, VDB Entry
http://packetstormsecurity.com/files/164629/Apache-2.4.49-2.4.50-Traversal-Remote-Code-Execution.htmlExploit, Third Party Advisory, VDB Entry
http://packetstormsecurity.com/files/164941/Apache-HTTP-Server-2.4.50-Remote-Code-Execution.htmlExploit, Third Party Advisory, VDB Entry
http://www.openwall.com/lists/oss-security/2021/10/05/2Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/07/1Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/07/6Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/08/1Exploit, Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/08/2Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/08/3Exploit, Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/08/4Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/08/5Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/08/6Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/09/1Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/11/4Mailing List, Patch, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/15/3Mailing List, Patch, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/16/1Mailing List, Third Party Advisory
https://httpd.apache.org/security/vulnerabilities_24.htmlRelease Notes, Vendor Advisory
https://lists.apache.org/thread.html/r17a4c6ce9aff662efd9459e9d1850ab4a611cb23392fc68264c72cb3%40%3Ccvs.httpd.apache.org%3EMailing List, Patch
https://lists.apache.org/thread.html/r6abf5f2ba6f1aa8b1030f95367aaf17660c4e4c78cb2338aee18982f%40%3Cusers.httpd.apache.org%3EMailing List
https://lists.apache.org/thread.html/r7c795cd45a3384d4d27e57618a215b0ed19cb6ca8eb070061ad5d837%40%3Cannounce.apache.org%3EMailing List
https://lists.apache.org/thread.html/r98d704ed4377ed889d40479db79ed1ee2f43b2ebdd79ce84b042df45%40%3Cannounce.apache.org%3EMailing List
https://lists.apache.org/thread.html/rb5b0e46f179f60b0c70204656bc52fcb558e961cb4d06a971e9e3efb%40%3Cusers.httpd.apache.org%3EMailing List
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RMIIEFINL6FUIOPD2A3M5XC6DH45Y3CC/Release Notes
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WS5RVHOIIRECG65ZBTZY7IEJVWQSQPG3/Release Notes
https://security.gentoo.org/glsa/202208-20Third Party Advisory
https://security.netapp.com/advisory/ntap-20211029-0009/Third Party Advisory
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-httpd-pathtrv-LAzg68cZThird Party Advisory
https://www.oracle.com/security-alerts/cpujan2022.htmlPatch, Third Party Advisory
http://packetstormsecurity.com/files/164418/Apache-HTTP-Server-2.4.49-Path-Traversal-Remote-Code-Execution.htmlExploit, Third Party Advisory, VDB Entry
http://packetstormsecurity.com/files/164418/Apache-HTTP-Server-2.4.49-Path-Traversal.htmlExploit, Third Party Advisory, VDB Entry
http://packetstormsecurity.com/files/164629/Apache-2.4.49-2.4.50-Traversal-Remote-Code-Execution.htmlExploit, Third Party Advisory, VDB Entry
http://packetstormsecurity.com/files/164941/Apache-HTTP-Server-2.4.50-Remote-Code-Execution.htmlExploit, Third Party Advisory, VDB Entry
http://www.openwall.com/lists/oss-security/2021/10/05/2Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/07/1Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/07/6Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/08/1Exploit, Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/08/2Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/08/3Exploit, Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/08/4Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/08/5Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/08/6Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/09/1Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/11/4Mailing List, Patch, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/15/3Mailing List, Patch, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/16/1Mailing List, Third Party Advisory
https://httpd.apache.org/security/vulnerabilities_24.htmlRelease Notes, Vendor Advisory
https://lists.apache.org/thread.html/r17a4c6ce9aff662efd9459e9d1850ab4a611cb23392fc68264c72cb3%40%3Ccvs.httpd.apache.org%3EMailing List, Patch
https://lists.apache.org/thread.html/r6abf5f2ba6f1aa8b1030f95367aaf17660c4e4c78cb2338aee18982f%40%3Cusers.httpd.apache.org%3EMailing List
https://lists.apache.org/thread.html/r7c795cd45a3384d4d27e57618a215b0ed19cb6ca8eb070061ad5d837%40%3Cannounce.apache.org%3EMailing List
https://lists.apache.org/thread.html/r98d704ed4377ed889d40479db79ed1ee2f43b2ebdd79ce84b042df45%40%3Cannounce.apache.org%3EMailing List
https://lists.apache.org/thread.html/rb5b0e46f179f60b0c70204656bc52fcb558e961cb4d06a971e9e3efb%40%3Cusers.httpd.apache.org%3EMailing List
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RMIIEFINL6FUIOPD2A3M5XC6DH45Y3CC/Release Notes
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WS5RVHOIIRECG65ZBTZY7IEJVWQSQPG3/Release Notes
https://security.gentoo.org/glsa/202208-20Third Party Advisory
https://security.netapp.com/advisory/ntap-20211029-0009/Third Party Advisory
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-httpd-pathtrv-LAzg68cZThird Party Advisory
https://www.oracle.com/security-alerts/cpujan2022.htmlPatch, Third Party Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-41773US Government Resource

Timeline

Published: Oct 5, 2021
Last modified: Jun 17, 2026
Added to CISA KEV: Nov 3, 2021
NVD status: Analyzed