The map_yp_alias function in functions/imap_general.php in SquirrelMail before 1.4.18 and NaSMail before 1.7 allows remote attackers to execute arbitrary commands via shell metacharacters in a username string that is used by the ypmatch program.
download.gna.org/nasmail/nasmail-1.7.zip
lists.apple.com/archives/security-announce/2010//Jun/msg00001.html
secunia.com/advisories/35052
secunia.com/advisories/35073
secunia.com/advisories/35140
secunia.com/advisories/35259
secunia.com/advisories/37415
secunia.com/advisories/40220
squirrelmail.svn.sourceforge.net/viewvc/squirrelmail/branches/SM-1_4-STABLE/squirrelmail/doc/ChangeLog
squirrelmail.svn.sourceforge.net/viewvc/squirrelmail/branches/SM-1_4-STABLE/squirrelmail/functions/imap_general.php?r1=13674&r2=13673&pathrev=13674
squirrelmail.svn.sourceforge.net/viewvc/squirrelmail?view=rev&revision=13674
support.apple.com/kb/HT4188
www.debian.org/security/2009/dsa-1802
www.mandriva.com/security/advisories?name=MDVSA-2009:110
www.redhat.com/support/errata/RHSA-2009-1066.html
www.securityfocus.com/bid/34916
www.squirrelmail.org/security/issue/2009-05-10
www.vupen.com/english/advisories/2009/1296
www.vupen.com/english/advisories/2009/3315
www.vupen.com/english/advisories/2010/1481
bugzilla.redhat.com/show_bug.cgi?id=500360
exchange.xforce.ibmcloud.com/vulnerabilities/50461
gna.org/forum/forum.php?forum_id=2146
oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A10986
www.redhat.com/archives/fedora-package-announce/2009-May/msg00566.html
www.redhat.com/archives/fedora-package-announce/2009-May/msg00572.html
www.redhat.com/archives/fedora-package-announce/2009-May/msg00577.html