CVE-2021-41773
CVSS v3
9.8
CRITICAL
EPSS Score
94.4 %
exploit probability
CISA KEV
Yes
known exploited
Exploitation
—
SSVC status
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.
CISA Known Exploited Vulnerability
- Date Added
- 2021-11-03
- Patch Due Date
- 2021-11-17
- Ransomware Use
- Known
Frequently asked questions
What is CVE-2021-41773?
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.
Is CVE-2021-41773 actively exploited?
Yes. CVE-2021-41773 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, meaning it has been confirmed as actively exploited in the wild. CISA requires federal agencies to patch by 11/17/2021.
What is the CVSS score for CVE-2021-41773?
CVE-2021-41773 has a CVSS v3 base score of 9.8 (CRITICAL severity).
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