# CVE-2021-42013: Path Traversal and Remote Code Execution in Apache HTTP Server 2.4.49 and 2.4.50 (incomplete fix of CVE-2021-41773)

> CVE-2021-42013: Path Traversal and Remote Code Execution in Apache HTTP Server 2.4.49 and 2.4.50 (incomplete fix of CVE-2021-41773). CVSS 9.8 (CVSS 3.1), in CISA KEV.

Canonical: https://rewindex.com/cve/CVE-2021-42013
Last updated: 2025-10-21T23:25:30Z

- Published: 2021-10-07 15:50 UTC · Updated: 2025-10-21 23:25 UTC · Assigner: apache
- CVSS: 9.8 (CVSS 3.1) · Severity: Critical · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS: 100.0%, 100th percentile (scored 2026-10-25)
- CISA KEV: yes, added 2021-11-03, federal due date 2021-11-17, ransomware use: Known
- CWE: CWE-22

## Description

It was found that the fix for CVE-2021-41773 in Apache HTTP Server 2.4.50 was insufficient. 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 only affects Apache 2.4.49 and Apache 2.4.50 and not earlier versions.

## CISA required action

Apply updates per vendor instructions.

## Affected vendors and products

- Apache Software Foundation: Apache HTTP Server

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2021-42013)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2021-42013)
- [http://jvn.jp/en/jp/JVN51106450/index.html](http://jvn.jp/en/jp/JVN51106450/index.html)
- [http://packetstormsecurity.com/files/164501/Apache-HTTP-Server-2.4.50-Path-Traversal-Code-Execution.html](http://packetstormsecurity.com/files/164501/Apache-HTTP-Server-2.4.50-Path-Traversal-Code-Execution.html)
- [http://packetstormsecurity.com/files/164609/Apache-HTTP-Server-2.4.50-Remote-Code-Execution.html](http://packetstormsecurity.com/files/164609/Apache-HTTP-Server-2.4.50-Remote-Code-Execution.html)
- [http://packetstormsecurity.com/files/164629/Apache-2.4.49-2.4.50-Traversal-Remote-Code-Execution.html](http://packetstormsecurity.com/files/164629/Apache-2.4.49-2.4.50-Traversal-Remote-Code-Execution.html)
- [http://packetstormsecurity.com/files/164941/Apache-HTTP-Server-2.4.50-Remote-Code-Execution.html](http://packetstormsecurity.com/files/164941/Apache-HTTP-Server-2.4.50-Remote-Code-Execution.html)
- [http://packetstormsecurity.com/files/165089/Apache-HTTP-Server-2.4.50-CVE-2021-42013-Exploitation.html](http://packetstormsecurity.com/files/165089/Apache-HTTP-Server-2.4.50-CVE-2021-42013-Exploitation.html)
- [http://packetstormsecurity.com/files/167397/Apache-2.4.50-Remote-Code-Execution.html](http://packetstormsecurity.com/files/167397/Apache-2.4.50-Remote-Code-Execution.html)
- [https://httpd.apache.org/security/vulnerabilities\_24.html](https://httpd.apache.org/security/vulnerabilities_24.html)
- [https://lists.apache.org/thread.html/r17a4c6ce9aff662efd9459e9d1850ab4a611cb23392fc68264c72cb3%40%3Ccvs.httpd.apache.org%3E](https://lists.apache.org/thread.html/r17a4c6ce9aff662efd9459e9d1850ab4a611cb23392fc68264c72cb3%2540%3Ccvs.httpd.apache.org%3E)
- [https://lists.apache.org/thread.html/r7c795cd45a3384d4d27e57618a215b0ed19cb6ca8eb070061ad5d837%40%3Cannounce.apache.org%3E](https://lists.apache.org/thread.html/r7c795cd45a3384d4d27e57618a215b0ed19cb6ca8eb070061ad5d837%2540%3Cannounce.apache.org%3E)
- [https://lists.apache.org/thread.html/rb5b0e46f179f60b0c70204656bc52fcb558e961cb4d06a971e9e3efb%40%3Cusers.httpd.apache.org%3E](https://lists.apache.org/thread.html/rb5b0e46f179f60b0c70204656bc52fcb558e961cb4d06a971e9e3efb%2540%3Cusers.httpd.apache.org%3E)
- [https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RMIIEFINL6FUIOPD2A3M5XC6DH45Y3CC/](https://lists.fedoraproject.org/archives/list/package-announce%2540lists.fedoraproject.org/message/RMIIEFINL6FUIOPD2A3M5XC6DH45Y3CC/)
- [https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WS5RVHOIIRECG65ZBTZY7IEJVWQSQPG3/](https://lists.fedoraproject.org/archives/list/package-announce%2540lists.fedoraproject.org/message/WS5RVHOIIRECG65ZBTZY7IEJVWQSQPG3/)
- [https://security.gentoo.org/glsa/202208-20](https://security.gentoo.org/glsa/202208-20)
- [https://security.netapp.com/advisory/ntap-20211029-0009/](https://security.netapp.com/advisory/ntap-20211029-0009/)
- [https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-httpd-pathtrv-LAzg68cZ](https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-httpd-pathtrv-LAzg68cZ)
- [https://www.oracle.com/security-alerts/cpuapr2022.html](https://www.oracle.com/security-alerts/cpuapr2022.html)
- [https://www.oracle.com/security-alerts/cpujan2022.html](https://www.oracle.com/security-alerts/cpujan2022.html)
- [https://www.povilaika.com/apache-2-4-50-exploit/](https://www.povilaika.com/apache-2-4-50-exploit/)
- [http://www.openwall.com/lists/oss-security/2021/10/07/6](http://www.openwall.com/lists/oss-security/2021/10/07/6)
- [http://www.openwall.com/lists/oss-security/2021/10/08/1](http://www.openwall.com/lists/oss-security/2021/10/08/1)
- [http://www.openwall.com/lists/oss-security/2021/10/08/2](http://www.openwall.com/lists/oss-security/2021/10/08/2)
- [http://www.openwall.com/lists/oss-security/2021/10/08/3](http://www.openwall.com/lists/oss-security/2021/10/08/3)
- [http://www.openwall.com/lists/oss-security/2021/10/08/4](http://www.openwall.com/lists/oss-security/2021/10/08/4)
- [http://www.openwall.com/lists/oss-security/2021/10/08/5](http://www.openwall.com/lists/oss-security/2021/10/08/5)
- [http://www.openwall.com/lists/oss-security/2021/10/08/6](http://www.openwall.com/lists/oss-security/2021/10/08/6)
- [http://www.openwall.com/lists/oss-security/2021/10/09/1](http://www.openwall.com/lists/oss-security/2021/10/09/1)
- [http://www.openwall.com/lists/oss-security/2021/10/11/4](http://www.openwall.com/lists/oss-security/2021/10/11/4)
- [http://www.openwall.com/lists/oss-security/2021/10/15/3](http://www.openwall.com/lists/oss-security/2021/10/15/3)
- [http://www.openwall.com/lists/oss-security/2021/10/16/1](http://www.openwall.com/lists/oss-security/2021/10/16/1)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2021-42013 · Markdown: https://rewindex.com/cve/CVE-2021-42013.md · JSON: https://rewindex.com/api/v1/cves/CVE-2021-42013 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T03:11:00.946Z