Follow Us

We use cookies to provide you with a better experience. If you continue to use this site, we'll assume you're happy with this. Alternatively, click here to find out how to manage these cookies

hide cookie message

Exim developers fix critical remote code execution vulnerability in email server

Exim 4.80.1 addresses vulnerability in DKIM handling code that could lead to system compromise

Article comments

Developers of the popular Exim email server software released an emergency update on Friday to address a critical vulnerability that could allow attackers to execute malicious code on the underlying operating system.

The vulnerability was located in the code responsible for performing DomainKeys Identified Mail (DKIM) verifications, a feature enabled by default in Exim installations.

DKIM allows associating domain names with email messages through the use of digital signatures that can be verified by the recipient email server. Its goal is to prevent email address spoofing.

The patched vulnerability is a heap-based buffer overflow and can be exploited by anyone who can send email from a domain name for which they control the DNS (Domain Name System) records, Exim developer Phil Pennock said Friday in an email announcing the release of Exim 4.80.1.

"This is a SECURITY release, addressing a CRITICAL remote code execution flaw in versions of Exim between 4.70 and 4.80 inclusive, when built with DKIM support," Pennock said.

The vulnerability is rated as critical and was identified during an internal review of the DKIM-related code in Exim.

The code review was prompted by two DKIM implementation issues that were disclosed last week and affected multiple email providers including Google, Microsoft and Yahoo.

"I apologize for the impact of releasing this on a Friday," Pennock said. "I do not consider there to be an acceptable alternative."

"I expect that this area of code in various MTAs [mail transfer agents] will be studied by many security conscious people around about now, so there is a significant risk that someone unfriendly has also discovered this, concurrently to our finding it," Pennock said.

Exim is one of the most popular mail transfer agents. It is installed by default in Debian Linux and other Debian-based Linux distributions like Ubuntu. It is also commonly used together with the popular Mailman mailing list software and the cPanel Web hosting server administration platform.

Most Linux vendors have already released updated Exim packages through their respective repositories, so users are encouraged to install them.



Share:

More from Techworld

More relevant IT news

Comments



Send to a friend

Email this article to a friend or colleague:

PLEASE NOTE: Your name is used only to let the recipient know who sent the story, and in case of transmission error. Both your name and the recipient's name and address will not be used for any other purpose.

Techworld White Papers

Choose – and Choose Wisely – the Right MSP for Your SMB

End users need a technology partner that provides transparency, enables productivity, delivers...

Download Whitepaper

10 Effective Habits of Indispensable IT Departments

It’s no secret that responsibilities are growing while budgets continue to shrink. Download this...

Download Whitepaper

Gartner Magic Quadrant for Enterprise Information Archiving

Enterprise information archiving is contributing to organisational needs for e-discovery and...

Download Whitepaper

Advancing the state of virtualised backups

Dell Software’s vRanger is a veteran of the virtualisation specific backup market. It was the...

Download Whitepaper

Techworld UK - Technology - Business

Innovation, productivity, agility and profit

Watch this on demand webinar which explores IT innovation, managed print services and business agility.

Techworld Mobile Site

Access Techworld's content on the move

Get the latest news, product reviews and downloads on your mobile device with Techworld's mobile site.

Find out more...

From Wow to How : Making mobile and cloud work for you

On demand Biztech Briefing - Learn how to effectively deliver mobile work styles and cloud services together.

Watch now...

Site Map

* *