Bug 2011900 (CVE-2021-42013) - CVE-2021-42013 httpd: path traversal and remote code execution (incomplete fix of CVE-2021-41773)
Summary: CVE-2021-42013 httpd: path traversal and remote code execution (incomplete fi...
Keywords:
Status: CLOSED NOTABUG
Alias: CVE-2021-42013
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 2011901
Blocks: 2000242
TreeView+ depends on / blocked
 
Reported: 2021-10-07 16:39 UTC by Guilherme de Almeida Suckevicz
Modified: 2021-10-25 08:51 UTC (History)
50 users (show)

Fixed In Version: httpd 2.4.51
Doc Type: If docs needed, set a value
Doc Text:
A path traversal and remote code execution flaw was found in Apache HTTP Server 2.4.49 and 2.4.50. A remote attacker could use this flaw to map URLs to files outside the expected document root. Additionally, this flaw could leak the source of interpreted files like CGI scripts. 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 paths, this could allow for remote code execution. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability. This is an incomplete fix for CVE-2021-41773.
Clone Of:
Environment:
Last Closed: 2021-10-15 02:09:08 UTC
Embargoed:

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Description Guilherme de Almeida Suckevicz 2021-10-07 16:39:33 UTC 
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.

Reference:
https://www.openwall.com/lists/oss-security/2021/10/07/6
Comment 1 Guilherme de Almeida Suckevicz 2021-10-07 16:40:02 UTC 
Created httpd tracking bugs for this issue:

Affects: fedora-all [bug 2011901]
Comment 7 Product Security DevOps Team 2021-10-15 02:09:08 UTC 
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):

https://access.redhat.com/security/cve/cve-2021-42013
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