Telstra CEO cites undocumented software change in Senate outage testimony

• Maintenance work triggered a software configuration that reset the device's date to 2006, causing authentication certificates to fail across Telstra's network and disrupting voice, data, and emergency services
• An intentional design change to fix a prior fault was never properly documented, leaving the maintenance team unaware of the equipment's behavior when restarted, and a critical software update had not been applied
• Brady stated the outage may have been prevented if either the software update had been completed or the design change properly documented, and Telstra will investigate why controls failed to capture and prioritize these known risks

Telstra CEO Explains Major Outage Caused by Software Failures

Telstra CEO Vicki Brady testified before a Senate inquiry on Friday, revealing that a major network outage last Wednesday resulted from an undocumented design change and a missed software update on a network time-keeping device.

Key Details:

The outage at Australia's largest telecommunications company disrupted phone services for thousands of customers, halted wireless payments, and stopped train operations. During maintenance work on network timing and synchronization equipment, a software configuration error reset the device's date to 2006, causing authentication certificates to fail across Telstra's entire network. This disrupted voice and data services, including critical Triple Zero emergency calls.

Root Cause:

Brady identified two critical failures: an intentional design change to fix a prior fault was not properly documented, leaving the maintenance team unaware of the device's behavior upon restart, and a necessary software update had not been applied. Brady stated that either proper documentation or completing the software update could have prevented the outage.

Broader Context:

This incident is the latest in a series of telecommunications failures affecting Australia. Optus, the country's second-largest telecom provider, experienced a major outage disrupting emergency call services last year, potentially causing four deaths. Optus also suffered a cyberattack exposing millions of customers' personal details and another outage that left millions without service for a day.

Next Steps:

Telstra's investigation will examine why the design change went undocumented, why the software update wasn't completed, and what control changes are needed to capture and prioritize known risks before they impact customers. Brady, who joined Telstra in 2016 from Optus, faces mounting pressure to improve system reliability.