Feeds

Yahoo! email! hijack! exploit!... Yours! for! $700!

Cybercrook: It's a bargain, guys... They usually cost way more

Beginner's guide to SSL certificates

A cross-site scripting (XSS) flaw on Yahoo! Mail creates a means to steal cookies and hijack accounts, according to a hacker who is offering to sell an alleged zero-day vulnerability exploit for $700.

The cybercrook, who uses the online nickname TheHell, knocked up a video to market the exploit which he is attempting to sell through Darkode, an underground cybercrime bazaar. The clip was captured and reposted on YouTube by security blogger Brian Krebs.

The video explains that the attack works by tricking a victim into clicking on a maliciously crafted link. This link supposedly exploits a cross-site scripting bug to steal the victim's Yahoo! mail cookies, which a cybercrook can later use to log into and hijack compromised Yahoo! webmail accounts.

TheHell claims the exploit works on all browsers and is a bargain at the not inconsiderable sum of $700.

I'm selling Yahoo stored xss that steal Yahoo emails cookies and works on ALL browsers. And you don’t need to bypass IE or Chrome xss filter as it do that itself because it’s stored xss. Prices around for such exploit is $1,100 – $1,500, while I offer it here for $700. Will sell only to trusted people cuz I don't want it to be patched soon!

Yahoo! is investigating the alleged vulnerability, following a tip-off from Krebs. The video advertising the exploit fails to explain which vulnerable URL would trigger the attack, something that's proving a little hard to pin down.

Yahoo!'s director of security, Ramses Martinez, told Krebs: "Fixing it is easy, most XSS are corrected by simple code change. ... Once we figure out the offending URL we can have new code deployed in a few hours at most."

Yahoo! has yet to respond to our request for an update on the situation. We'll update this story as and when we hear more.

XSS flaws are a perennial web security problem that are a permanent fixture in the Open Web Application Security Project's (OWASP) list of Top 10 Application Security Risks. Top tips for guarding against this class of vulnerability by OWASP can be found here.

Xssed.com, a site that collates reported XSS attacks, has several previous examples of XSS flaws on Yahoo! pages and hundreds of examples of flaws on other sites. Scripting bugs vary greatly in their potency, so judging impact by numbers alone is bound to be misleading.

More commentary on the Yahoo! webmail flaws and cross-site scripting more generally can be found in a blog post by Lisa Vaas for the Sophos Naked Security blog here. ®

Choosing a cloud hosting partner with confidence

More from The Register

next story
SMASH the Bash bug! Apple and Red Hat scramble for patch batches
'Applying multiple security updates is extremely difficult'
Apple's new iPhone 6 vulnerable to last year's TouchID fingerprint hack
But unsophisticated thieves need not attempt this trick
Hackers thrash Bash Shellshock bug: World races to cover hole
Update your gear now to avoid early attacks hitting the web
Oracle SHELLSHOCKER - data titan lists unpatchables
Database kingpin lists 32 products that can't be patched (yet) as GNU fixes second vuln
Who.is does the Harlem Shake
Blame it on LOLing XSS terroristas
Researchers tell black hats: 'YOU'RE SOOO PREDICTABLE'
Want to register that domain? We're way ahead of you.
Stunned by Shellshock Bash bug? Patch all you can – or be punished
UK data watchdog rolls up its sleeves, polishes truncheon
Ello? ello? ello?: Facebook challenger in DDoS KNOCKOUT
Gets back up again after half an hour though
prev story

Whitepapers

Providing a secure and efficient Helpdesk
A single remote control platform for user support is be key to providing an efficient helpdesk. Retain full control over the way in which screen and keystroke data is transmitted.
Intelligent flash storage arrays
Tegile Intelligent Storage Arrays with IntelliFlash helps IT boost storage utilization and effciency while delivering unmatched storage savings and performance.
Beginner's guide to SSL certificates
De-mystify the technology involved and give you the information you need to make the best decision when considering your online security options.
Security for virtualized datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.
Secure remote control for conventional and virtual desktops
Balancing user privacy and privileged access, in accordance with compliance frameworks and legislation. Evaluating any potential remote control choice.