YouTube hack 'threatened' Justin Bieber videos
A Russian coder has revealed how he discovered a way to delete any video on YouTube.
A demonstration of Kamil Hismatullin's technique, posted online, shows that once he had copied part of a video's web address he could use it to wipe the clip within half a minute.
Rather than exploit the hack, he instead reported it to parent company Google, which gave him a reward.
He joked, however, that he was tempted to wipe Justin Bieber's music videos.
"I spent six to seven hours [on] research, considering that [for a] couple of hours I've fought the urge to clean up Bieber's channel, haha," wrote Mr Hismatullin.
"Although it was an early Saturday's (sic) morning in San Francisco when I reported [the] issue, Google's security team replied very fast, since this vulnerability could create utter havoc in a matter of minutes in the bad hands.
"This vulnerability [might have been used] to extort people or simply disrupt YouTube by deleting massive amounts of videos in a very short period of time.
"It was fixed in several hours, Google rewarded me $5,000 and luckily no Bieber videos were harmed."
Mr Hismatullin wrote that he discovered the flaw while investigating YouTube Creator Studio, a service that lets video creators see analytics data about the clips they have uploaded via an app.
The facility allows any clip to be deleted if you type in both its event ID - which can be found in its web address - and a long string of letters and numbers known as an authentication token, which is supposed to act as a kind of password.
The problem the coder discovered was that the service was accepting any token for a takedown request, rather than requiring one that belonged to the account of the person who had uploaded the clip.
This meant Mr Hismatullin could simply copy a token from his own account and use it to delete others' videos.
The developer said that he had spent time searching for vulnerabilities in Google's products after previously having been given a $1,337 (£902) grant by the firm.
The search giant gives such payouts as part of a programme to encourage people who have previously reported flaws to hunt out more.
The scheme puts a cap on subsequent payments, limiting the bounty Mr Hismatullin received for his findings.
"To be honest I expected $15,000 to $20,000," he commented.
"I wanted to write a kind of 'complaint' to Google, but first I re-read [its] rules and understood that Google could not pay me more.
"Facebook has not got a boundary for maximum reward, so they can pay as much as they want."