Multiple remote buffer overflow vulnerabilities in Courier — GLSA 200403-06

Remote buffer overflow vulnerabilities have been found in Courier-IMAP and Courier MTA. These exploits may allow the execution of abritrary code, allowing unauthorized access to a vulnerable system.

Affected packages

Package 	net-mail/courier-imap on all architectures
Affected versions 	< 3.0.0
Unaffected versions 	>= 3.0.0
Package 	mail-mta/courier on all architectures
Affected versions 	< 0.45
Unaffected versions 	>= 0.45

Background

Courier MTA is a multiprotocol mail server suite that provides webmail, mailing lists, IMAP, and POP3 services. Courier-IMAP is a standalone server that gives IMAP access to local mailboxes.

Description

The vulnerabilities have been found in the 'SHIFT_JIS' converter in 'shiftjis.c' and 'ISO2022JP' converter in 'so2022jp.c'. An attacker may supply Unicode characters that exceed BMP (Basic Multilingual Plane) range, causing an overflow.

Impact

An attacker without privileges may exploit this vulnerability remotely, allowing arbitrary code to be executed in order to gain unauthorized access.

Workaround

While a workaround is not currently known for this issue, all users are advised to upgrade to the latest version of the affected packages.

Resolution

All users should upgrade to current versions of the affected packages:

 # emerge sync

 # emerge -pv ">=net-mail/courier-imap-3.0.0"
 # emerge ">=net-mail/courier-imap-3.0.0"

 # ** Or; depending on your installation... **

 # emerge -pv ">=mail-mta/courier-0.45"
 # emerge ">=mail-mta/courier-0.45"
 

References

    Courier Multiple Remote Buffer Overflow Vulnerabilities
    CAN-2004-0224