SEC Consult Vulnerability Lab Security Advisory < 20190829-0 > ======================================================================= title: Hardcoded FTP Credentials product: Zyxel NWA/NAP/WAC wireless access point series vulnerable version: see "Vulnerable / tested version" fixed version: see "Solution" CVE number: - impact: medium homepage: https://www.zyxel.com found: 2019-06-19 by: Thomas Weber (Office Vienna) IoT Inspector SEC Consult Vulnerability Lab An integrated part of SEC Consult Europe | Asia | North America https://www.sec-consult.com ======================================================================= Vendor description: ------------------- "Focused on innovation and customer-centricity, Zyxel Communications Corp. has been connecting people to the internet for nearly 30 years. We keep promoting creativity which meets the needs of customers. This spirit has never been changed since we developed the world's first integrated 3-in-1 data/fax/voice modem in 1992. Our ability to adapt and innovate with networking technology places us at the forefront of understanding connectivity for telco/service providers, businesses and home users. We're building the networks of tomorrow, helping unlock the world's potential and meeting the needs of the modern workplace; powering people at work, life and play. We stand side-by-side with our customers and partners to share new approaches to networking that will unleash their abilities. Loyal friend, powerful ally, reliable resource — we are Zyxel, Your Networking Ally." Source: https://www.zyxel.com/about_zyxel/company_overview.shtml Business recommendation: ------------------------ SEC Consult recommends Zyxel customers to upgrade the firmware to the latest version available. A thorough security review should be performed by security professionals to identify further potential security issues. Vulnerability overview/description: ----------------------------------- 1) Hardcoded FTP Credentials An FTP service runs on the Zyxel wireless access point that contains the configuration file for the WiFi network. This FTP server can be accessed with hardcoded credentials that are embedded in the firmware of the AP. When the WiFi network is bound to another VLAN, an attacker can cross the network by fetching the credentials from the FTP server. The credentials were found by doing an automated scan with IoT Inspector. Proof of concept: ----------------- 1) Hardcoded FTP Credentials The username "devicehaecived" and the password "1234" can be used to access the FTP server of the AP on port 21. The content of the FTP server looks like the following listing: ------------------------------------------------------------------------------- $ ls cert conf debug idp packet_trace script tmp wtp_image ------------------------------------------------------------------------------- The directory "conf" contains all configuration files which store the WiFi SSIDs and passphrases. Vulnerable / tested versions: ----------------------------- The following versions have been manually tested and were automatically verified with IoT Inspector: Zyxel NWA5121-NI 5.50 patch 0 and earlier Zyxel NWA5121-N 5.50 patch 0 and earlier The vendor provided the following list of affected devices: Zyxel WAC6103D-I 5.50 patch 0 and earlier Zyxel WAC6303D-S 5.50 patch 0 and earlier Zyxel WAC6502D-E 5.50 patch 0 and earlier Zyxel WAC6502D-S 5.50 patch 0 and earlier Zyxel WAC6503D-S 5.50 patch 0 and earlier Zyxel WAC6553D-E 5.50 patch 0 and earlier Zyxel WAC6552D-S 5.50 patch 0 and earlier Zyxel WAC5302D-S 5.50 patch 0 and earlier Zyxel NWA5123-AC 5.50 patch 0 and earlier Zyxel NWA5123-AC HD 5.50 patch 0 and earlier Zyxel NWA5123-NI 5.50 patch 0 and earlier Zyxel NWA5301-NJ 5.50 patch 0 and earlier Zyxel NWA1302-AC 5.50 patch 0 and earlier Zyxel NWA1123-ACv2 5.50 patch 0 and earlier Zyxel NWA1123-AC HD 5.50 patch 0 and earlier Zyxel NWA1123-AC PRO 5.50 patch 0 and earlier Zyxel NAP102 5.50 patch 0 and earlier Zyxel NAP203 5.50 patch 0 and earlier Zyxel NAP303 5.50 patch 0 and earlier Zyxel NAP353 5.50 patch 0 and earlier Vendor contact timeline: ------------------------ 2019-06-26: Contacting vendor through security@zyxel.com.tw. 2019-06-27: Vendor changed PGP key. Sent advisory with new key. Vendor confirmed receipt. 2019-07-03: Asked for an update; Vendor told that they just finished their investigation. 2019-07-09: Vendor provided a full list of devices that are prone to this vulnerability. 2019-07-23: Asked for a timeline; Vendor asked to shift the release of the advisory to 2019-08-29 in order to provide fixes; Shifted advisory release to this date. 2019-08-26: Asked for a status update; Vendor told that fixes are ready to be published at 2019-08-29. 2019-08-29: Coordinated advisory release. Solution: --------- Install the newest firmware for your device from the vendor's website to fix this issue: https://www.zyxel.com/support/download_landing.shtml Additionally, the vendor provides the following security notice: https://www.zyxel.com/support/hardcoded-FTP-credential-vulnerability-of-access-points.shtml Workaround: ----------- Restrict network access to the web interface. Advisory URL: ------------- https://www.sec-consult.com/en/vulnerability-lab/advisories/index.html ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ SEC Consult Vulnerability Lab SEC Consult Europe | Asia | North America 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 / @2019