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)
At a glance
- Severity
- CRITICAL 9.8
- Exploitation
- Known exploited (CISA KEV) · added 2021-11-03
Exploited per ENISA since 2021-11-03 - EPSS
- EPSS 99.96 % · percentile 100 (2026-10-27)
- State
- PUBLISHED
- Published
- Updated
- Assigner
- apache
- NVD status
- Analyzed
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.
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | CRITICAL 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | CISA-ADP |
| CVSS 3.1 | CRITICAL 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | NVD · nvd@nist.gov (Primary) |
| CVSS 3.1 | CRITICAL 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | NVD · 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Secondary) |
| CVSS 2.0 | HIGH 7.5 | AV:N/AC:L/Au:N/C:P/I:P/A:P | NVD · nvd@nist.gov (Primary) |
Weaknesses (CWE)
European references
- ENISA EUVD · EUVD-2021-29001
- GCVE · GCVE-0-2021-42013
CERT-FR advisories
- CERTFR-2024-AVI-0575 — Multiples vulnérabilités dans les produits Juniper Networks · cert.ssi.gouv.fr
- CERTFR-2021-AVI-764 — Vulnérabilité dans Apache HTTP Server · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:a:apache:http_server:2.4.49:*:*:*:*:*:*:*cpe:2.3:a:apache:http_server:2.4.50:*:*:*:*:*:*:*cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*cpe:2.3:a:oracle:instantis_enterprisetrack:17.1:*:*:*:*:*:*:*cpe:2.3:a:oracle:instantis_enterprisetrack:17.2:*:*:*:*:*:*:*cpe:2.3:a:oracle:instantis_enterprisetrack:17.3:*:*:*:*:*:*:*cpe:2.3:a:oracle:jd_edwards_enterpriseone_tools:*:*:*:*:*:*:*:*< 9.2.6.0cpe:2.3:a:oracle:secure_backup:*:*:*:*:*:*:*:*< 18.1.0.1.0cpe:2.3:a:netapp:cloud_backup:-:*:*:*:*:*:*:*
Affected products
| Product | Versions |
|---|---|
| Apache Software Foundation · Apache HTTP Server | affected Apache HTTP Server 2.4.49 ; affected Apache HTTP Server 2.4.50 |
References
- https://httpd.apache.org/security/vulnerabilities_24.html
- https://lists.apache.org/thread.html/r7c795cd45a3384d4d27e57618a215b0ed19cb6ca8eb070061ad5d837%40%3Cannounce.apache.org%3E
- https://lists.apache.org/thread.html/rb5b0e46f179f60b0c70204656bc52fcb558e961cb4d06a971e9e3efb%40%3Cusers.httpd.apache.org%3E
- http://www.openwall.com/lists/oss-security/2021/10/07/6
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-httpd-pathtrv-LAzg68cZ
- http://jvn.jp/en/jp/JVN51106450/index.html
- http://www.openwall.com/lists/oss-security/2021/10/08/1
- https://lists.apache.org/thread.html/r17a4c6ce9aff662efd9459e9d1850ab4a611cb23392fc68264c72cb3%40%3Ccvs.httpd.apache.org%3E
- 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/2021/10/08/4
- http://www.openwall.com/lists/oss-security/2021/10/08/6
- http://www.openwall.com/lists/oss-security/2021/10/08/5
- http://www.openwall.com/lists/oss-security/2021/10/09/1
- http://www.openwall.com/lists/oss-security/2021/10/11/4
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RMIIEFINL6FUIOPD2A3M5XC6DH45Y3CC/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WS5RVHOIIRECG65ZBTZY7IEJVWQSQPG3/
- http://www.openwall.com/lists/oss-security/2021/10/15/3
- http://www.openwall.com/lists/oss-security/2021/10/16/1
- https://www.oracle.com/security-alerts/cpujan2022.html
- https://security.netapp.com/advisory/ntap-20211029-0009/
- 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/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/165089/Apache-HTTP-Server-2.4.50-CVE-2021-42013-Exploitation.html
- https://www.oracle.com/security-alerts/cpuapr2022.html
- http://packetstormsecurity.com/files/167397/Apache-2.4.50-Remote-Code-Execution.html
- https://www.povilaika.com/apache-2-4-50-exploit/
- https://security.gentoo.org/glsa/202208-20
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-42013
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| CISA Known Exploited Vulnerabilities | CC0 1.0 |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |