-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 ### Device Details Discovered By: Andrew Klaus (andrew@aklaus.ca) Vendor: Actiontec (Telus Branded, but may work on others) Model: WEB6000Q Affected Firmware: 1.1.02.22 Reported: Sept 2018 CVE: Not needed since update is pushed by the provider. ### Summary of Findings The wireless extenders use DHCP Option 125 to include device details such as model number, manufacturer, and serial number. The WCB6000Q DHCP DISCOVER and REQUEST broadcasts include the device serial number in the DHCP option 125 (subopt 2) field. An attacker on the same Layer 2 network segment as the device, can see all these DHCP requests with a packet capture. Once he or she has this, the device’s admin web UI password can be reset using the web UI “forgot password” page to reset to a known value. ### Mitigation Do not use the serial number to initiate password resets. The serial number has other internal uses in the Web UI, which means there’s a higher chance of it being leaked over the network. By using a different value, this risk can be mitigated since the reset value is only used for that purpose. -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEE/rRUDraOzqmrp8tZoyRid8jQfpkFAlz9UTIACgkQoyRid8jQ fpkVMRAA0fwfRQbpvp4/nsuqKrqmB8pGB8pLkw12LEC2nDwRnkq0qyTSlN34/7dA I+nSYGdqPZgDp/1lv1RmLuow42U7wNhFMy7zNElNyNrrztB57ItAJEBon9U2mtAh 4cQd6u4i+qFOKEag2o810+nUAR2QNAi5vMkwrvQtiElXhhunDDk22jci8QN/YndP eb7j1BAygCL6BGZOuiUkv+2sXlGYHY+BfeV+wciTIvvevV1Bnrlmf1YNydnQKkfu unDtRfvGsUsg3YDbMcO5Uq3I1A7yFuH/Ai0uEtmQKkG9rELYiZkT0iW+n4TrFvts xw8GnANacBo3bITExs7zCiLL/uuv4H8gRyRM8ydnOv8ZiVZajYN3QxQ6EHoMnFq5 JrNN9vMtmvrNkRarzsyUWEPHL2PPJIf9KLh2mnUtNaoTO0kD1ra/gK4JgJM6ra5Y EQfz7keaaI6zUvQKfnTZE57qglh5IY64CC3HAf3KtmLOzivCXCzNb1hjajd0X3Ax gwQMuR5b/SdvqV3uA3hbJs/cL61Qc892iNmJgMaKRpLBeDOVKVF7Ztww4VJtlNtf 2a7isPX0Pt5h3b/PuT3v2/OEEi7dgB5bXTqCKlE8j2nXMIrFH6DL6eojeIp+wZzP UZ1eikvjwQCqtzTAFTYrCjv9Ss/FWtuYOzbksfJmNuTF+j9nBt8= =GA42 -----END PGP SIGNATURE-----