The remote host is missing an update to squirrelmail announced via advisory DSA 535-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%20535-1

Four vulnerabilities were discovered in squirrelmail: CVE-2004-0519 - Multiple cross-site scripting (XSS) vulnerabilities in SquirrelMail 1.4.2 allow remote attackers to execute arbitrary script as other users and possibly steal authentication information via multiple attack vectors, including the mailbox parameter in compose.php. CVE-2004-0520 - Cross-site scripting (XSS) vulnerability in mime.php for SquirrelMail before 1.4.3 allows remote attackers to insert arbitrary HTML and script via the content-type mail header, as demonstrated using read_body.php. CVE-2004-0521 - SQL injection vulnerability in SquirrelMail before 1.4.3 RC1 allows remote attackers to execute unauthorized SQL statements, with unknown impact, probably via abook_database.php. CVE-2004-0639 - Multiple cross-site scripting (XSS) vulnerabilities in Squirrelmail 1.2.10 and earlier allow remote attackers to inject arbitrary HTML or script via (1) the $mailer variable in read_body.php, (2) the $senderNames_part variable in mailbox_display.php, and possibly other vectors including (3) the $event_title variable or (4) the $event_text variable. For the current stable distribution (woody), these problems have been fixed in version 1:1.2.6-1.4. For the unstable distribution (sid), these problems have been fixed in 2:1.4.3a-0.1 and earlier versions. We recommend that you update your squirrelmail package.