A number of major broadband providers across the UK, including the 'big six' - BT, PlusNet, EE, Virgin Media, Sky Broadband and TalkTalk - could be vulnerable to having their systems exploited by hackers.
This is the main finding of a new report from security consultant Paul Moore, which used publicly available information to audit a number of different areas, such as email systems, website servers and HTML forms.
Each provider was then scored on each aspect depending on the level of support for various security features.
Providers passed 87 of the checks, but there were 22 warnings and 84 failures in terms of good security practice.
TalkTalk, which recently suffered a high-profile hacking scandal, was the only firm to record a “critical issue”, having left itself exposed to a potential Database Credential Leak.
The related database is now offline but it will nevertheless be seen as another unwelcome blow to the company.
Under "serious issues", there was just one problem found on Sky Broadband, while EE and PlusNet were exposed to two.
TalkTalk emerged top with a total of four serious issues, while BT and Virgin Media were not found to have any serious problems.
In terms of overall standings, BT was rated the best for security, closely followed by Plusnet.
Sky Broadband came third, receiving praise for its quick response to the issues raised and then making “significant improvements to their TLS deployment.”
However, results for the bottom three were less impressive, with the report particularly critical of Virgin's inability to "engage in any security-related discussion...the sole exception being a SuperHub 2 vulnerability last year."
It added that TalkTalk was currently operating "in a bubble of blissful ignorance", before concluding: "Their utterly shambolic approach to security, combined with a proclivity to make wild & demonstrably fallacious claims, places TalkTalk firmly in last place during this audit."
With regard to EE, the report stated: "Unfortunately, EE have one of the weakest overall deployments, saved only by their willingness to discuss these issues so candidly."