Critical Exim Mail Server Vulnerability Exposes Millions to Malicious Attachments
Jul 12, 2024
Vulnerability / Software Security
A critical security issue has been disclosed in the Exim mail transfer agent that could enable threat actors to deliver malicious attachments to target users' inboxes. The vulnerability , tracked as CVE-2024-39929, has a CVSS score of 9.1 out of 10.0. It has been addressed in version 4.98. "Exim through 4.97.1 misparses a multiline RFC 2231 header filename, and thus remote attackers can bypass a $mime_filename extension-blocking protection mechanism, and potentially deliver executable attachments to the mailboxes of end users," according to a description shared on the U.S. National Vulnerability Database (NVD). Exim is a free, mail transfer agent that's used in hosts that are running Unix or Unix-like operating systems. It was first released in 1995 for use at the University of Cambridge. Attack surface management firm Censys said 4,830,719 of the 6,540,044 public-facing SMTP mail servers are running Exim. As of July 12, 2024, 1,563,085 internet-accessible