SquirrelMail is a webmail package written in PHP. It supports IMAP and SMTP protocols.
SquirrelMail does not validate the right_frame parameter in webmail.php, possibly allowing frame replacement or cross-site scripting (CVE-2006-0188). Martijn Brinkers and Scott Hughes discovered that MagicHTML fails to handle certain input correctly, potentially leading to cross-site scripting (only Internet Explorer, CVE-2006-0195). Vicente Aguilera reported that the sqimap_mailbox_select function did not strip newlines from the mailbox or subject parameter, possibly allowing IMAP command injection (CVE-2006-0377).
By exploiting the cross-site scripting vulnerabilities, an attacker can execute arbitrary scripts running in the context of the victim's browser. This could lead to a compromise of the user's webmail account, cookie theft, etc. A remote attacker could exploit the IMAP command injection to execute arbitrary IMAP commands on the configured IMAP server.
There is no known workaround at this time.
All SquirrelMail users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=mail-client/squirrelmail-1.4.6"
Note: Users with the vhosts USE flag set should manually use webapp-config to finalize the update.