Connect with us

Hi, what are you looking for?

SecurityWeekSecurityWeek

Cybercrime

Tech Support Scammers Exploiting Unpatched Firefox Bug

Mozilla is working on addressing a Firefox bug that has been exploited by tech support scammers to lock the browser when users visit specially crafted websites.

Mozilla is working on addressing a Firefox bug that has been exploited by tech support scammers to lock the browser when users visit specially crafted websites.

Attacks were spotted recently by Jérôme Segura of Malwarebytes, who told SecurityWeek that there are currently two known Firefox bugs that have been abused in tech support scams.

Exploitation only requires that users visit the websites set up by the cybercrooks. These sites display warnings and instruct victims to call “Windows support” at a specified number.

Firefox tech support scam

Segura informed Mozilla of one bug, which has the bug ID 1438214, two years ago, when a very similar flaw had been exploited by scammers against Chrome users. The flaw allows an attacker to freeze the browser by exploiting the download blob API in a way that consumes all CPU resources.

The researcher recently decided to revisit this bug and discovered that it remains unfixed. He also identified a newer bug that has also been exploited by tech support scammers.

“The newer bug abuses notifications by perpetually asking users for the same authorization,” Segura told SecurityWeek, explaining that this flaw appears to be a variation of a previously fixed issue that involved authentication pop-ups and which had been exploited for years.

Based on information in the new bug report created by Segura, Mozilla has known about this issue for at least three months — Mozilla developers flagged Segura’s report as a duplicate — but a fix has yet to be released.

Mozilla has not responded to SecurityWeek’s request for comment, but based on discussions in the bug reports, a patch is expected to be included in Firefox 71, which is scheduled for release on December 3.

Advertisement. Scroll to continue reading.

Until a patch becomes available, users who encounter the scam websites can forcefully close Firefox from the Task Manager on Windows or using the Force Quit option on macOS — the bug affects Firefox on both Windows and macOS.

Related: Vulnerability Patched in Firefox Password Manager

Related: Firefox Zero-Day Vulnerability Exploited in Targeted Attacks

Related: Mozilla Hardens Firefox Against Injection Attacks

Written By

Eduard Kovacs (@EduardKovacs) is a managing editor at SecurityWeek. He worked as a high school IT teacher for two years before starting a career in journalism as Softpedia’s security news reporter. Eduard holds a bachelor’s degree in industrial informatics and a master’s degree in computer techniques applied in electrical engineering.

Click to comment

Trending

Daily Briefing Newsletter

Subscribe to the SecurityWeek Email Briefing to stay informed on the latest threats, trends, and technology, along with insightful columns from industry experts.

Understand how to go beyond effectively communicating new security strategies and recommendations.

Register

Join us for an in depth exploration of the critical nature of software and vendor supply chain security issues with a focus on understanding how attacks against identity infrastructure come with major cascading effects.

Register

Expert Insights

Related Content

Vulnerabilities

Less than a week after announcing that it would suspended service indefinitely due to a conflict with an (at the time) unnamed security researcher...

Cybercrime

The changing nature of what we still generally call ransomware will continue through 2023, driven by three primary conditions.

Cybercrime

As it evolves, web3 will contain and increase all the security issues of web2 – and perhaps add a few more.

Cybercrime

A recently disclosed vBulletin vulnerability, which had a zero-day status for roughly two days last week, was exploited in a hacker attack targeting the...

Cybercrime

Luxury retailer Neiman Marcus Group informed some customers last week that their online accounts had been breached by hackers.

Data Breaches

OpenAI has confirmed a ChatGPT data breach on the same day a security firm reported seeing the use of a component affected by an...

IoT Security

A group of seven security researchers have discovered numerous vulnerabilities in vehicles from 16 car makers, including bugs that allowed them to control car...

Vulnerabilities

A researcher at IOActive discovered that home security systems from SimpliSafe are plagued by a vulnerability that allows tech savvy burglars to remotely disable...