Hardcoded usernames and passwords have been discovered in a recent line of Telstra broadband routers that could allow attackers access to customer networks.

SC was tipped off to the public disclosure of the flaws on 16 October, 2012, and given the threat posed to Telstra customers, had warned Telstra and delayed publication until the telco and vendor Netcomm had developed and fully tested a firmware fix.

The flaws meant attackers could bypass any unique passwords and access the device administrative console and customer's local network.

Telstra has today issued a patch to fix the flaws and was contacting affected customers by phone and email to urge them to apply the fix.

The firmware upgrade was the only means of removing the unchangeable default logins introduced by Netcomm into the BigPond Elite Wireless BroadBand Network Gateway line.

"We’ve now published a firmware update and are contacting all customers with this type of modem to ensure they install the patch," Telstra told SC in a statement.

"...we’ve worked as quickly as possible with our vendor to design, create, test and deploy a software update for our customers."

Milan-based security researcher and consultant Roberto Paleari discovered the flaws and publicly disclosed them on 12 October after he told SC he reported it to a Telstra Bigpond technical support line.

Paleari later worked with Telstra and Netcomm to detail the vulnerabilities, which also included a command-injection flaw due to the server-side script failing to properly validate user-supplied input.

The researcher publicly disclosed the holes after he said Telstra's technical support department requested he detail the bug over phone and would not communicate via email, his preferred method for record-keeping.

“I can only say I am really sorry I finally had to disclose the vulnerabilities without waiting for a fix from the device manufacturer,” Paleari told SC, adding that he believed in responsible disclosure.

“Router security should be taken more seriously.”

SC urges all affected users to apply the patch immediately.

The patch also introduced a feature allowing manual selection between internal and external antennas from the modem interface.