CVE-2021-42013

critical-risk
Published 2021-10-07

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.

Do I need to act?

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94.4% chance of exploitation in next 30 days
EPSS score — higher than 6% of all CVEs
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CISA KEV: actively exploited in the wild
On the Known Exploited Vulnerabilities catalog — federal agencies must patch
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3 public exploits available
50406, 50446, 50512
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
9
CVSS 9.8/10 Critical
NETWORK / LOW complexity

Affected Products (10)

Affected Vendors

Apache Oracle Fedoraproject Netapp

References (61)

Third Party Advisory http://jvn.jp/en/jp/JVN51106450/index.html
Exploit http://packetstormsecurity.com/files/164501/Apache-HTTP-Server-2.4.50-Path-Trave...
Exploit http://packetstormsecurity.com/files/164609/Apache-HTTP-Server-2.4.50-Remote-Cod...
Exploit http://packetstormsecurity.com/files/164629/Apache-2.4.49-2.4.50-Traversal-Remot...
Exploit http://packetstormsecurity.com/files/164941/Apache-HTTP-Server-2.4.50-Remote-Cod...
Third Party Advisory http://packetstormsecurity.com/files/165089/Apache-HTTP-Server-2.4.50-CVE-2021-4...
Exploit http://packetstormsecurity.com/files/167397/Apache-2.4.50-Remote-Code-Execution....
Mailing List http://www.openwall.com/lists/oss-security/2021/10/07/6
Mailing List http://www.openwall.com/lists/oss-security/2021/10/08/1
Mailing List http://www.openwall.com/lists/oss-security/2021/10/08/2
Mailing List http://www.openwall.com/lists/oss-security/2021/10/08/3
Mailing List http://www.openwall.com/lists/oss-security/2021/10/08/4
Mailing List http://www.openwall.com/lists/oss-security/2021/10/08/5
Mailing List http://www.openwall.com/lists/oss-security/2021/10/08/6
Mailing List http://www.openwall.com/lists/oss-security/2021/10/09/1
Mailing List http://www.openwall.com/lists/oss-security/2021/10/11/4
Mailing List http://www.openwall.com/lists/oss-security/2021/10/15/3
Mailing List http://www.openwall.com/lists/oss-security/2021/10/16/1
Release Notes https://httpd.apache.org/security/vulnerabilities_24.html
Mailing List https://lists.apache.org/thread.html/r17a4c6ce9aff662efd9459e9d1850ab4a611cb2339...
and 41 more references
82
/ 100
critical-risk
Severity 32/34 · Critical
Exploitability 34/34 · Critical
Exposure 16/34 · Moderate