Apache · HTTP Server
CVE-2021-41773
Path traversal and file disclosure vulnerability in Apache HTTP Server 2.4.49
O que é
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.
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. The original patch issued under this CVE ID is insufficient, please review remediation information under CVE-2021-42013.
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
- 5 de outubro de 2021
- Gravidade
- Alto 7,5 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://httpd.apache.org/security/vulnerabilities_24.html
- https://lists.apache.org/thread.html/r6abf5f2ba6f1aa8b1030f95367aaf17660c4e4c78cb2338aee18982f%40%3Cusers.htt…
- https://lists.apache.org/thread.html/r98d704ed4377ed889d40479db79ed1ee2f43b2ebdd79ce84b042df45%40%3Cannounce.…
- http://www.openwall.com/lists/oss-security/2021/10/05/2
- http://www.openwall.com/lists/oss-security/2021/10/07/1
- 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://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://packetstormsecurity.com/files/164418/Apache-HTTP-Server-2.4.49-Path-Traversal.html
- http://packetstormsecurity.com/files/164418/Apache-HTTP-Server-2.4.49-Path-Traversal-Remote-Code-Execution.ht…
- http://www.openwall.com/lists/oss-security/2021/10/11/4
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 | Crítica 9,8 | >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.