Apache · HTTP Server
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)
O que é
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: Apache HTTP Server contains a path traversal vulnerability that allows an attacker to perform remote code execution if files outside directories configured by Alias-like directives are not under default require all denied or if CGI scripts are enabled. This CVE ID resolves an incomplete patch for CVE-2021-41773.
O que fazer
Apply updates per vendor instructions.
Prazo para as agências federais dos EUA: 17 de novembro de 2021
- Adicionada à lista da CISA
- 3 de novembro de 2021
- Publicada
- 7 de outubro de 2021
- Gravidade
- Crítica 9,8 CVSS 3.1
- Chance de ataques nos próximos 30 dias (EPSS)
- >99,9% entre os 0,1% mais altos de todas as vulnerabilidades conhecidas
- Fraqueza
- CWE-22
- Mais detalhes
- NVD · CVE.org · CISA
Todas as referências (20)
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-httpd-pathtrv-LAzg68cZ
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RMIIEFINL6FU…
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WS5RVHOIIREC…
- https://httpd.apache.org/security/vulnerabilities_24.html
- https://lists.apache.org/thread.html/r7c795cd45a3384d4d27e57618a215b0ed19cb6ca8eb070061ad5d837%40%3Cannounce.…
- https://lists.apache.org/thread.html/rb5b0e46f179f60b0c70204656bc52fcb558e961cb4d06a971e9e3efb%40%3Cusers.htt…
- http://www.openwall.com/lists/oss-security/2021/10/07/6
- 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…
- 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
- 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
Mais falhas exploradas de Apache
| Adicionado | Vulnerabilidade | Produto | Gravidade | Chance de ataque |
|---|---|---|---|---|
| 1 de mai. de 2025 | Improper Escaping of Output | HTTP Server | Crítica 9,1 | >99,9% |
| 3 de nov. de 2021 | Privilege Escalation | HTTP Server | Alto 7,8 | 65% |
| 3 de nov. de 2021 | Path Traversal | HTTP Server | Alto 7,5 | >99,9% |
| 8 de out. de 2026 | Command Injection | Struts | Alto 8,1 | 97% |
| 4 de ago. de 2026 | Missing Encryption of Sensitive Data | Tomcat | Alto 7,5 | 99% |
| 16 de abr. de 2026 | Improper Input Validation | ActiveMQ | Alto 8,8 | 98% |
| 1 de abr. de 2025 | Path Equivalence | Tomcat | Crítica 10,0 | 99,9% |
| 4 de fev. de 2025 | Forced Browsing | OFBiz | Crítica 9,8 | >99,9% |
Fontes: Known Exploited Vulnerabilities (CISA, domínio público), CVE records (cve.org) e EPSS (FIRST). A chance de ataque é a estimativa EPSS de que alguém tente explorar a falha nos próximos 30 dias.