FreeBSD : Apache httpd -- Path Traversal and Remote Code Execution (d001c189-2793-11ec-8fb1-206a8a720317) - Nessus

Critical   Plugin ID: 153983

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This page contains detailed information about the FreeBSD : Apache httpd -- Path Traversal and Remote Code Execution (d001c189-2793-11ec-8fb1-206a8a720317) Nessus plugin including available exploits and PoCs found on GitHub, in Metasploit or Exploit-DB for verifying of this vulnerability.

Plugin Overview

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ID: 153983
Name: FreeBSD : Apache httpd -- Path Traversal and Remote Code Execution (d001c189-2793-11ec-8fb1-206a8a720317)
Filename: freebsd_pkg_d001c189279311ec8fb1206a8a720317.nasl
Vulnerability Published: 2021-10-07
This Plugin Published: 2021-10-11
Last Modification Time: 2022-01-26
Plugin Version: 1.7
Plugin Type: local
Plugin Family: FreeBSD Local Security Checks
Dependencies: ssh_get_info.nasl
Required KB Items [?]: Host/FreeBSD/pkg_info, Host/FreeBSD/release, Host/local_checks_enabled

Vulnerability Information

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Severity: Critical
Vulnerability Published: 2021-10-07
Patch Published: 2021-10-07
CVE [?]: CVE-2021-42013
CPE [?]: cpe:/o:freebsd:freebsd, p-cpe:/a:freebsd:freebsd:apache24

Synopsis

The remote FreeBSD host is missing a security-related update.

Description

The Apache http server project reports :

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

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

Solution

Update the affected package.

Public Exploits

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Target Network Port(s): N/A
Target Asset(s): N/A
Exploit Available: True (Metasploit Framework, Exploit-DB, GitHub, D2 Elliot)
Exploit Ease: Exploits are available

Here's the list of publicly known exploits and PoCs for verifying the FreeBSD : Apache httpd -- Path Traversal and Remote Code Execution (d001c189-2793-11ec-8fb1-206a8a720317) vulnerability:

1. Metasploit: auxiliary/scanner/http/apache_normalize_path
   [Apache 2.4.49/2.4.50 Traversal RCE]
2. Metasploit: exploit/multi/http/apache_normalize_path_rce
   [Apache 2.4.49/2.4.50 Traversal RCE]
3. Metasploit: auxiliary/scanner/http/apache_normalize_path
   [Apache 2.4.49/2.4.50 Traversal RCE scanner]
4. Exploit-DB: exploits/multiple/webapps/50406.sh
   [EDB-50406: Apache HTTP Server 2.4.50 - Path Traversal & Remote Code Execution (RCE)]
5. Exploit-DB: exploits/multiple/webapps/50446.sh
   [EDB-50446: Apache HTTP Server 2.4.50 - Remote Code Execution (RCE) (2)]
6. Exploit-DB: exploits/multiple/webapps/50512.py
   [EDB-50512: Apache HTTP Server 2.4.50 - Remote Code Execution (RCE) (3)]
7. GitHub: https://github.com/0day666/Vulnerability-verification
   [CVE-2021-42013]
8. GitHub: https://github.com/Adash7/CVE-2021-42013
   [CVE-2021-42013]
9. GitHub: https://github.com/BincangSiber/CVE-2021-42013
   [CVE-2021-42013]
10. GitHub: https://github.com/CHYbeta/Vuln100Topics20
    [CVE-2021-42013]
11. GitHub: https://github.com/CalfCrusher/Path-traversal-RCE-Apache-2.4.49-2.4.50-Exploit
    [CVE-2021-42013: CVE-2021-41773]
12. GitHub: https://github.com/FDlucifer/firece-fish
    [CVE-2021-42013]
13. GitHub: https://github.com/H0j3n/EzpzCheatSheet
    [CVE-2021-42013]
14. GitHub: https://github.com/H0j3n/EzpzShell
    [CVE-2021-42013]
15. GitHub: https://github.com/LayarKacaSiber/CVE-2021-42013
    [CVE-2021-42013]
16. GitHub: https://github.com/Ls4ss/CVE-2021-41773_CVE-2021-42013
    [CVE-2021-42013]
17. GitHub: https://github.com/Mr-xn/Penetration_Testing_POC
    [CVE-2021-42013]
18. GitHub: https://github.com/Shadow-warrior0/Apache_path_traversal
    [CVE-2021-42013]
19. GitHub: https://github.com/Zeop-CyberSec/apache_normalize_path
    [CVE-2021-42013]
20. GitHub: https://github.com/ahmad4fifz/CVE-2021-41773
    [CVE-2021-42013]
21. GitHub: https://github.com/asaotomo/CVE-2021-42013-Apache-RCE-POC-EXP
    [CVE-2021-42013: Apache HTTP ...]
22. GitHub: https://github.com/asaotomo/CVE-2021-42013-Apache-RCE-Poc-Exp
    [CVE-2021-42013: Apache 远程代码执行 （CVE-2021-42013）批量检测工具：Apache HTTP ...]
23. GitHub: https://github.com/cryst4lliz3/CVE-2021-42013
    [CVE-2021-42013]
24. GitHub: https://github.com/honypot/CVE-2021-42013
    [CVE-2021-42013]
25. GitHub: https://github.com/ibrahimetecicek/Advent-of-Cyber-3-2021-
    [CVE-2021-42013]
26. GitHub: https://github.com/im-hanzou/apachrot
    [CVE-2021-42013]
27. GitHub: https://github.com/jas9reet/CVE-2021-42013-LAB
    [CVE-2021-42013: Apache HTTP Server 2.4.50 - RCE Lab]
28. GitHub: https://github.com/ksanchezcld/httpd-2.4.49
    [CVE-2021-42013]
29. GitHub: https://github.com/ltfafei/my_POC
    [CVE-2021-42013]
30. GitHub: https://github.com/mr-exo/CVE-2021-41773
    [CVE-2021-42013]
31. GitHub: https://github.com/pisut4152/Sigma-Rule-for-CVE-2021-41773-and-CVE-2021-42013-exploitation-attempt
    [CVE-2021-42013]
32. GitHub: https://github.com/rnsss/CVE-2021-42013
    [CVE-2021-42013: CVE-2021-42013-exp]
33. GitHub: https://github.com/simon242/CVE-2021-42013
    [CVE-2021-42013]
34. GitHub: https://github.com/tangxiaofeng7/CVE-2022-22947-Spring-Cloud-Gateway
    [CVE-2021-42013: CVE-2021-42013批量]
35. GitHub: https://github.com/twseptian/CVE-2021-41773
    [CVE-2021-42013]
36. GitHub: https://github.com/twseptian/CVE-2021-42013-Lab
    [CVE-2021-42013: Docker container lab to play/learn with CVE-2021-42013]
37. GitHub: https://github.com/twseptian/cve-2021-42013-docker-lab
    [CVE-2021-42013: Docker container lab to play/learn with CVE-2021-42013]
38. GitHub: https://github.com/vulf/CVE-2021-41773_42013
    [CVE-2021-42013]
39. GitHub: https://github.com/walnutsecurity/CVE-2021-42013
    [CVE-2021-42013: cve-2021-42013.py is a python script that will help in finding Path Traversal or ...]
40. GitHub: https://github.com/wangfly-me/Apache_Penetration_Tool
    [CVE-2021-42013: CVE-2021-41773&CVE-2021-42013]
41. GitHub: https://github.com/xMohamed0/CVE-2021-42013-ApacheRCE
    [CVE-2021-42013]
42. GitHub: https://github.com/5gstudent/cve-2021-41773-and-cve-2021-42013
    [CVE-2021-42013: cve-2021-41773 即 cve-2021-42013 批量检测脚本]
43. GitHub: https://github.com/ahmad4fifz/CVE-2021-42013
    [CVE-2021-42013: CVE-2021-41773 on Docker]
44. GitHub: https://github.com/andrea-mattioli/apache-exploit-CVE-2021-42013
    [CVE-2021-42013: Exploit with integrated shodan search]
45. GitHub: https://github.com/corelight/CVE-2021-41773
    [CVE-2021-42013: A Zeek package which raises notices for Path Traversal/RCE in Apache HTTP Server ...]
46. GitHub: https://github.com/Hydragyrum/CVE-2021-41773-Playground
    [CVE-2021-42013: Some docker images to play with CVE-2021-41773 and CVE-2021-42013]
47. GitHub: https://github.com/IcmpOff/Apache-2.4.49-2.4.50-Traversal-Remote-Code-Execution-Exploit
    [CVE-2021-42013: This Metasploit module exploits an unauthenticated remote code execution ...]
48. GitHub: https://github.com/inbug-team/CVE-2021-41773_CVE-2021-42013
    [CVE-2021-42013: CVE-2021-41773 CVE-2021-42013漏洞批量检测工具]
49. GitHub: https://github.com/mauricelambert/CVE-2021-42013
    [CVE-2021-42013: These Nmap, Python and Ruby scripts detects and exploits CVE-2021-42013 with RCE and ...]
50. GitHub: https://github.com/MrCl0wnLab/SimplesApachePathTraversal
    [CVE-2021-42013: Tool check: CVE-2021-41773, CVE-2021-42013, CVE-2020-17519]
51. GitHub: https://github.com/robotsense1337/CVE-2021-42013
    [CVE-2021-42013: Exploit Apache 2.4.50(CVE-2021-42013)]
52. GitHub: https://github.com/TheLastVvV/CVE-2021-42013_Reverse-Shell
    [CVE-2021-42013: PoC CVE-2021-42013 reverse shell Apache 2.4.50 with CGI]
53. GitHub: https://github.com/theLSA/apache-httpd-path-traversal-checker
    [CVE-2021-42013: apache httpd path traversal checker(CVE-2021-41773 / CVE-2021-42013)]
54. GitHub: https://github.com/twseptian/CVE-2021-42013-Docker-Lab
    [CVE-2021-42013: Docker container lab to play/learn with CVE-2021-42013]
55. GitHub: https://github.com/Vulnmachines/cve-2021-42013
    [CVE-2021-42013: Apache 2.4.50 Path traversal vulnerability]
56. GitHub: https://github.com/walnutsecurity/cve-2021-42013
    [CVE-2021-42013: Cve-2021-42013.py is a python script that will help in finding Path Traversal or ...]
57. D2 Elliot: apache_2.4.50_rce.html
    [Apache 2.4.50 RCE]

Before running any exploit against any system, make sure you are authorized by the owner of the target system(s) to perform such activity. In any other case, this would be considered as an illegal activity.

WARNING: Beware of using unverified exploits from sources such as GitHub or Exploit-DB. These exploits and PoCs could contain malware. For more information, see how to use exploits safely.

Risk Information

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CVSS Score Source [?]: CVE-2021-42013
CVSS V2 Vector: AV:N/AC:L/Au:N/C:P/I:P/A:P/E:H/RL:OF/RC:C

CVSS Base Score:	7.5 (High)
Impact Subscore:	6.4
Exploitability Subscore:	10.0
CVSS Temporal Score:	6.5 (Medium)
CVSS Environmental Score:	NA (None)
Modified Impact Subscore:	NA
Overall CVSS Score:	6.5 (Medium)

CVSS V3 Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:H/RL:O/RC:C

CVSS Base Score:	9.8 (Critical)
Impact Subscore:	5.9
Exploitability Subscore:	3.9
CVSS Temporal Score:	9.4 (Critical)
CVSS Environmental Score:	NA (None)
Modified Impact Subscore:	NA
Overall CVSS Score:	9.4 (Critical)

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Plugin Source

---

This is the freebsd_pkg_d001c189279311ec8fb1206a8a720317.nasl nessus plugin source code. This script is Copyright (C) 2021-2022 and is owned by Tenable, Inc. or an Affiliate thereof.

#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from the FreeBSD VuXML database :
#
# Copyright 2003-2021 Jacques Vidrine and contributors
#
# Redistribution and use in source (VuXML) and 'compiled' forms (SGML,
# HTML, PDF, PostScript, RTF and so forth) with or without modification,
# are permitted provided that the following conditions are met:
# 1. Redistributions of source code (VuXML) must retain the above
#    copyright notice, this list of conditions and the following
#    disclaimer as the first lines of this file unmodified.
# 2. Redistributions in compiled form (transformed to other DTDs,
#    published online in any format, converted to PDF, PostScript,
#    RTF and other formats) must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer
#    in the documentation and/or other materials provided with the
#    distribution.
# 
# THIS DOCUMENTATION IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
# THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
# BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
# OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
# OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
# BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
# WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
# OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS DOCUMENTATION,
# EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#

include('deprecated_nasl_level.inc');
include('compat.inc');

if (description)
{
  script_id(153983);
  script_version("1.7");
  script_set_attribute(attribute:"plugin_modification_date", value:"2022/01/26");

  script_cve_id("CVE-2021-42013");
  script_xref(name:"CISA-KNOWN-EXPLOITED", value:"2021/11/17");

  script_name(english:"FreeBSD : Apache httpd -- Path Traversal and Remote Code Execution (d001c189-2793-11ec-8fb1-206a8a720317)");

  script_set_attribute(attribute:"synopsis", value:
"The remote FreeBSD host is missing a security-related update.");
  script_set_attribute(attribute:"description", value:
"The Apache http server project reports :

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

Acknowledgements: Reported by Juan Escobar from Dreamlab Technologies,
Fernando Munoz from NULL Life CTF Team, and Shungo Kumasaka");
  # https://vuxml.freebsd.org/freebsd/d001c189-2793-11ec-8fb1-206a8a720317.html
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?4c28c816");
  script_set_attribute(attribute:"solution", value:
"Update the affected package.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:H/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:H/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-42013");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"d2_elliot_name", value:"Apache 2.4.50 RCE");
  script_set_attribute(attribute:"exploit_framework_d2_elliot", value:"true");
  script_set_attribute(attribute:"metasploit_name", value:'Apache 2.4.49/2.4.50 Traversal RCE');
  script_set_attribute(attribute:"exploit_framework_metasploit", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2021/10/07");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/10/07");
  script_set_attribute(attribute:"plugin_publication_date", value:"2021/10/11");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:freebsd:freebsd:apache24");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:freebsd:freebsd");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"FreeBSD Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 2021-2022 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/FreeBSD/release", "Host/FreeBSD/pkg_info");

  exit(0);
}


include("audit.inc");
include("freebsd_package.inc");


if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item("Host/FreeBSD/release")) audit(AUDIT_OS_NOT, "FreeBSD");
if (!get_kb_item("Host/FreeBSD/pkg_info")) audit(AUDIT_PACKAGE_LIST_MISSING);


flag = 0;

if (pkg_test(save_report:TRUE, pkg:"apache24>=2.4.49<2.4.51")) flag++;

if (flag)
{
  if (report_verbosity > 0) security_hole(port:0, extra:pkg_report_get());
  else security_hole(0);
  exit(0);
}
else audit(AUDIT_HOST_NOT, "affected");

The latest version of this script can be found in these locations depending on your platform:

• Linux / Unix:
  /opt/nessus/lib/nessus/plugins/freebsd_pkg_d001c189279311ec8fb1206a8a720317.nasl
• Windows:
  C:\ProgramData\Tenable\Nessus\nessus\plugins\freebsd_pkg_d001c189279311ec8fb1206a8a720317.nasl
• Mac OS X:
  /Library/Nessus/run/lib/nessus/plugins/freebsd_pkg_d001c189279311ec8fb1206a8a720317.nasl

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How to Run

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Here is how to run the FreeBSD : Apache httpd -- Path Traversal and Remote Code Execution (d001c189-2793-11ec-8fb1-206a8a720317) as a standalone plugin via the Nessus web user interface (https://localhost:8834/):

1. Click to start a New Scan.
2. Select Advanced Scan.
3. Navigate to the Plugins tab.
4. On the top right corner click to Disable All plugins.
5. On the left side table select FreeBSD Local Security Checks plugin family.
6. On the right side table select FreeBSD : Apache httpd -- Path Traversal and Remote Code Execution (d001c189-2793-11ec-8fb1-206a8a720317) plugin ID 153983.
7. Specify the target on the Settings tab and click to Save the scan.
8. Run the scan.

Here are a few examples of how to run the plugin in the command line. Note that the examples below demonstrate the usage on the Linux / Unix platform.

Basic usage:

/opt/nessus/bin/nasl freebsd_pkg_d001c189279311ec8fb1206a8a720317.nasl -t <IP/HOST>

Run the plugin with audit trail message on the console:

/opt/nessus/bin/nasl -a freebsd_pkg_d001c189279311ec8fb1206a8a720317.nasl -t <IP/HOST>

Run the plugin with trace script execution written to the console (useful for debugging):

/opt/nessus/bin/nasl -T - freebsd_pkg_d001c189279311ec8fb1206a8a720317.nasl -t <IP/HOST>

Run the plugin with using a state file for the target and updating it (useful for running multiple plugins on the target):

/opt/nessus/bin/nasl -K /tmp/state freebsd_pkg_d001c189279311ec8fb1206a8a720317.nasl -t <IP/HOST>

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References

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See also:

• https://www.tenable.com/plugins/nessus/153983
• http://www.nessus.org/u?4c28c816
• https://vulners.com/nessus/FREEBSD_PKG_D001C189279311EC8FB1206A8A720317.NASL

Similar and related Nessus plugins:

• 154179 - Amazon Linux 2 : httpd (ALAS-2021-1716)
• 154188 - Amazon Linux AMI : httpd24 (ALAS-2021-1543)
• 155600 - Apache HTTP Server 2.4.49 & 2.4.50 Path Traversal (CVE-2021-42013)
• 153952 - Apache 2.4.49 < 2.4.51 Path Traversal Vulnerability

Version

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This page has been produced using Nessus Professional 10.1.2 (#68) LINUX, Plugin set 202205072148.
Plugin file freebsd_pkg_d001c189279311ec8fb1206a8a720317.nasl version 1.7. For more plugins, visit the Nessus Plugin Library.

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