Vulnerability 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.
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Apache | Http Server | 2.4.49 |
| Fedoraproject | Fedora | 34 |
| Oracle | Instantis Enterprisetrack | 17.1 |
| Netapp | Cloud Backup | - |
Related Weaknesses (CWE)
References
- http://packetstormsecurity.com/files/164418/Apache-HTTP-Server-2.4.49-Path-TraveExploitThird Party AdvisoryVDB Entry
- http://packetstormsecurity.com/files/164418/Apache-HTTP-Server-2.4.49-Path-TraveExploitThird Party AdvisoryVDB Entry
- http://packetstormsecurity.com/files/164629/Apache-2.4.49-2.4.50-Traversal-RemotExploitThird Party AdvisoryVDB Entry
- http://packetstormsecurity.com/files/164941/Apache-HTTP-Server-2.4.50-Remote-CodExploitThird Party AdvisoryVDB Entry
- http://www.openwall.com/lists/oss-security/2021/10/05/2Mailing ListThird Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/07/1Mailing ListThird Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/07/6Mailing ListThird Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/08/1ExploitMailing ListThird Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/08/2Mailing ListThird Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/08/3ExploitMailing ListThird Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/08/4Mailing ListThird Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/08/5Mailing ListThird Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/08/6Mailing ListThird Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/09/1Mailing ListThird Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/11/4Mailing ListPatchThird Party Advisory
FAQ
What is CVE-2021-41773?
CVE-2021-41773 is a vulnerability with a CVSS score of 9.8 (CRITICAL). 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-lik...
How severe is CVE-2021-41773?
CVE-2021-41773 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2021-41773?
Check the references section above for vendor advisories and patch information. Affected products include: Apache Http Server, Fedoraproject Fedora, Oracle Instantis Enterprisetrack, Netapp Cloud Backup.