[SA20519] Courier Mail Server Username Encoding Denial of Service

---

Want to join the Secunia Security Team?

Secunia offers a position as a security specialist, where your daily
work involves reverse engineering of software and exploit code,
auditing of source code, and analysis of vulnerability reports.

http://secunia.com/secunia_security_specialist/

---

TITLE:
Courier Mail Server Username Encoding Denial of Service

SECUNIA ADVISORY ID:
SA20519

VERIFY ADVISORY:
http://secunia.com/advisories/20519/

CRITICAL:
Moderately critical

IMPACT:
DoS

WHERE:
>From remote

SOFTWARE:
Courier Mail Server 0.x
http://secunia.com/product/2557/

DESCRIPTION:
A vulnerability has been reported in Courier Mail Server, which
potentially can be exploited by malicious people to cause a DoS
(Denial of Service).

The vulnerability is caused due to an error within the encoding of
usernames that contain the "=" character. This can potentially be
exploited to cause a DoS by consuming large amount of CPU resources.

The vulnerability has been reported in versions prior to 0.53.2.

SOLUTION:
Update to version 0.53.2 or apply patch.
http://www.courier-mta.org/?download.php

Patch:
http://www.courier-mta.org/beta/patches/verp-fix/verp.patch.txt

PROVIDED AND/OR DISCOVERED BY:
Reported by vendor.

ORIGINAL ADVISORY:
http://www.courier-mta.org/beta/patches/verp-fix/README.txt
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=368834

---

About:
This Advisory was delivered by Secunia as a free service to help
everybody keeping their systems up to date against the latest
vulnerabilities.

Subscribe:
http://secunia.com/secunia_security_advisories/

Definitions: (Criticality, Where etc.)
http://secunia.com/about_secunia_advisories/

Please Note:
Secunia recommends that you verify all advisories you receive by
clicking the link.
Secunia NEVER sends attached files with advisories.
Secunia does not advise people to install third party patches, only
use those supplied by the vendor.