ESB-2017.3006 - ALERT [Linux][Ubuntu] exim4: Execute arbitrary code/commands - Remote/unauthenticated 2017-11-28

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             AUSCERT External Security Bulletin Redistribution

                               ESB-2017.3006
                            Exim vulnerability
                             28 November 2017

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        AusCERT Security Bulletin Summary
        ---------------------------------

Product:           exim4
Publisher:         Ubuntu
Operating System:  Ubuntu
                   Linux variants
Impact/Access:     Execute Arbitrary Code/Commands -- Remote/Unauthenticated
                   Denial of Service               -- Remote/Unauthenticated
Resolution:        Patch/Upgrade
CVE Names:         CVE-2017-16943  

Original Bulletin: 
   http://www.ubuntu.com/usn/usn-3493-1

Comment: This advisory references vulnerabilities in products which run on 
         platforms other than Ubuntu. It is recommended that administrators 
         running exim4 check for an updated version of the software for their
         operating system. Please note: There is exploit code publically 
         available for this vulnerablity.

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USN-3493-1: Exim vulnerability

Ubuntu Security Notice USN-3493-1

27th November, 2017

exim4 vulnerability

A security issue affects these releases of Ubuntu and its derivatives:

Ubuntu 17.10

Ubuntu 17.04

Summary

Exim could be made to crash or run programs if it received specially crafted 
network traffic.

Software description

exim4 - Exim is a mail transport agent

Details

It was discovered that Exim incorrectly handled memory in the ESMTP

CHUNKING extension. A remote attacker could use this issue to cause Exim to

crash, resulting in a denial of service, or possibly execute arbitrary

code. The default compiler options for affected releases should reduce the

vulnerability to a denial of service.

Update instructions

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

Ubuntu 17.10:

exim4-daemon-heavy 4.89-5ubuntu1.1

exim4-daemon-light 4.89-5ubuntu1.1

Ubuntu 17.04:

exim4-daemon-heavy 4.88-5ubuntu1.2

exim4-daemon-light 4.88-5ubuntu1.2

To update your system, please follow these instructions: 
https://wiki.ubuntu.com/Security/Upgrades.

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

References

CVE-2017-16943

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