CRITICAL CISA KEV

CVE-2021-42013

CVSS v3

9.8

CRITICAL

EPSS Score

94.4%

exploit probability

CISA KEV

Yes

known exploited

Exploitation

SSVC status

Description

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.

CISA Known Exploited Vulnerability

Date Added
11/3/2021
Patch Due Date
11/17/2021
Ransomware Use
Known

Technical details

Published
10/7/2021

Frequently asked questions

What is CVE-2021-42013?

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.

Is CVE-2021-42013 actively exploited?

Yes. CVE-2021-42013 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-2021-42013?

CVE-2021-42013 has a CVSS v3 base score of 9.8 (CRITICAL severity).

Is CVE-2021-42013 affecting your environment?

Use isMalicious to check if any of your IPs or domains are associated with this vulnerability's IOCs.