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

Title:Multiple remote buffer overflow vulnerabilities in Courier
Bugs: #45584


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.


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.

Affected packages

Package Vulnerable Unaffected Architecture(s)
net-mail/courier-imap < 3.0.0 >= 3.0.0 All supported architectures
mail-mta/courier < 0.45 >= 0.45 All supported architectures


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.


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


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


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"



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