CVE-2021-41773
Last modified
CVE-2021-41773 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. 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. CISA has confirmed active exploitation in the wild. EPSS estimates a 99.99% chance of exploitation in the next 30 days.
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.
Metrics
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Exploitation Status
This vulnerability is listed in CISA’s Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. Federal agencies must remediate by .
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Apache | Http Server | 2.4.49 |
| Fedoraproject | Fedora | 34 |
| Fedoraproject | Fedora | 35 |
| Oracle | Instantis Enterprisetrack | 17.1 |
| Oracle | Instantis Enterprisetrack | 17.2 |
| Oracle | Instantis Enterprisetrack | 17.3 |
| Netapp | Cloud Backup | All versions |
References
- http://packetstormsecurity.com/files/164418/Apache-HTTP-Server-2.4.49-Path-Traversal-Remote-Code-Execution.htmlExploit, Third Party Advisory, VDB Entry
- http://packetstormsecurity.com/files/164418/Apache-HTTP-Server-2.4.49-Path-Traversal.htmlExploit, Third Party Advisory, VDB Entry
- http://packetstormsecurity.com/files/164629/Apache-2.4.49-2.4.50-Traversal-Remote-Code-Execution.htmlExploit, Third Party Advisory, VDB Entry
- http://packetstormsecurity.com/files/164941/Apache-HTTP-Server-2.4.50-Remote-Code-Execution.htmlExploit, Third Party Advisory, VDB Entry
- http://www.openwall.com/lists/oss-security/2021/10/05/2Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/07/1Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/07/6Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/08/1Exploit, Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/08/2Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/08/3Exploit, Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/08/4Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/08/5Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/08/6Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/09/1Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/11/4Mailing List, Patch, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/15/3Mailing List, Patch, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/16/1Mailing List, Third Party Advisory
- https://httpd.apache.org/security/vulnerabilities_24.htmlRelease Notes, Vendor Advisory
- https://security.gentoo.org/glsa/202208-20Third Party Advisory
- https://security.netapp.com/advisory/ntap-20211029-0009/Third Party Advisory
- https://www.oracle.com/security-alerts/cpujan2022.htmlPatch, Third Party Advisory
- http://packetstormsecurity.com/files/164418/Apache-HTTP-Server-2.4.49-Path-Traversal-Remote-Code-Execution.htmlExploit, Third Party Advisory, VDB Entry
- http://packetstormsecurity.com/files/164418/Apache-HTTP-Server-2.4.49-Path-Traversal.htmlExploit, Third Party Advisory, VDB Entry
- http://packetstormsecurity.com/files/164629/Apache-2.4.49-2.4.50-Traversal-Remote-Code-Execution.htmlExploit, Third Party Advisory, VDB Entry
- http://packetstormsecurity.com/files/164941/Apache-HTTP-Server-2.4.50-Remote-Code-Execution.htmlExploit, Third Party Advisory, VDB Entry
- http://www.openwall.com/lists/oss-security/2021/10/05/2Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/07/1Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/07/6Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/08/1Exploit, Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/08/2Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/08/3Exploit, Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/08/4Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/08/5Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/08/6Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/09/1Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/11/4Mailing List, Patch, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/15/3Mailing List, Patch, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/10/16/1Mailing List, Third Party Advisory
- https://httpd.apache.org/security/vulnerabilities_24.htmlRelease Notes, Vendor Advisory
- https://security.gentoo.org/glsa/202208-20Third Party Advisory
- https://security.netapp.com/advisory/ntap-20211029-0009/Third Party Advisory
- https://www.oracle.com/security-alerts/cpujan2022.htmlPatch, Third Party Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-41773US Government Resource
Timeline
- Published
- Last Modified
- Status
- Analyzed
Frequently Asked Questions
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