USN-6939-1: Exim vulnerability

Publication date

31 July 2024

Overview

Exim could be made to bypass a MIME filename extension-blocking protection mechanism if it received specially crafted input.


Packages

  • exim4 - Exim is a mail transport agent

Details

Phillip Szelat discovered that Exim misparses multiline MIME header
filenames. A remote attacker could use this issue to bypass a MIME filename
extension-blocking protection mechanism and possibly deliver executable
attachments to the mailboxes of end users.

Phillip Szelat discovered that Exim misparses multiline MIME header
filenames. A remote attacker could use this issue to bypass a MIME filename
extension-blocking protection mechanism and possibly deliver executable
attachments to the mailboxes of end users.

Update instructions

In general, a standard system update will make all the necessary changes.

Learn more about how to get the fixes.

The problem can be corrected by updating your system to the following package versions:

Ubuntu Release Package Version
24.04 noble exim4 –  4.97-4ubuntu4.1
exim4-base –  4.97-4ubuntu4.1
eximon4 –  4.97-4ubuntu4.1
22.04 jammy exim4 –  4.95-4ubuntu2.6
exim4-base –  4.95-4ubuntu2.6
eximon4 –  4.95-4ubuntu2.6
20.04 focal exim4 –  4.93-13ubuntu1.12
exim4-base –  4.93-13ubuntu1.12
eximon4 –  4.93-13ubuntu1.12
18.04 bionic exim4 –  4.90.1-1ubuntu1.10+esm5  
exim4-base –  4.90.1-1ubuntu1.10+esm5  
eximon4 –  4.90.1-1ubuntu1.10+esm5  
16.04 xenial exim4 –  4.86.2-2ubuntu2.6+esm8  
exim4-base –  4.86.2-2ubuntu2.6+esm8  
eximon4 –  4.86.2-2ubuntu2.6+esm8  

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