SquirrelMail 1.4.22 (and other versions before 20170427_0200-SVN) allows post-authentication remote code execution via a sendmail.cf file that is mishandled in a popen call. It's possible to exploit this vulnerability to execute arbitrary shell commands on the remote server. The problem is in the Deliver_SendMail.class.php with the initStream function that uses escapeshellcmd() to sanitize the sendmail command before executing it. The use of escapeshellcmd() is not correct in this case since it doesn't escape whitespaces, allowing the injection of arbitrary command parameters. The problem is in -f$envelopefrom within the sendmail command line. Hence, if the target server uses sendmail and SquirrelMail is configured to use it as a command-line program, it's possible to trick sendmail into using an attacker-provided configuration file that triggers the execution of an arbitrary command. For exploitation, the attacker must upload a sendmail.cf file as an email attachment, and inject the …

functions/imap_general.php in SquirrelMail, as used in Red Hat Enterprise Linux (RHEL) 4 and 5, does not properly handle 8-bit characters in passwords, which allows remote attackers to cause a denial of service (disk consumption) by making many IMAP login attempts with different usernames, leading to the creation of many preference files. NOTE: this issue exists because of an incorrect fix for CVE-2010-2813.

CRLF injection vulnerability in SquirrelMail 1.4.21 and earlier allows remote attackers to modify or add preference values via a \n (newline) character, a different vulnerability than CVE-2010-4555.

Multiple cross-site request forgery (CSRF) vulnerabilities in SquirrelMail 1.4.21 and earlier allow remote attackers to hijack the authentication of unspecified victims via vectors involving (1) the empty trash implementation and (2) the Index Order (aka options_order) page, a different issue than CVE-2010-4555.

functions/page_header.php in SquirrelMail 1.4.21 and earlier does not prevent page rendering inside a frame in a third-party HTML document, which makes it easier for remote attackers to conduct clickjacking attacks via a crafted web site.

Multiple cross-site scripting (XSS) vulnerabilities in SquirrelMail 1.4.21 and earlier allow remote attackers to inject arbitrary web script or HTML via vectors involving (1) drop-down selection lists, (2) the > (greater than) character in the SquirrelSpell spellchecking plugin, and (3) errors associated with the Index Order (aka options_order) page.

Cross-site scripting (XSS) vulnerability in functions/mime.php in SquirrelMail before 1.4.22 allows remote attackers to inject arbitrary web script or HTML via a crafted STYLE element in an e-mail message.

functions/imap_general.php in SquirrelMail before 1.4.21 does not properly handle 8-bit characters in passwords, which allows remote attackers to cause a denial of service (disk consumption) by making many IMAP login attempts with different usernames, leading to the creation of many preferences files.

The Mail Fetch plugin in SquirrelMail 1.4.20 and earlier allows remote authenticated users to bypass firewall restrictions and use SquirrelMail as a proxy to scan internal networks via a modified POP3 port number.

Multiple cross-site request forgery (CSRF) vulnerabilities in SquirrelMail 1.4.19 and earlier, and NaSMail before 1.7, allow remote attackers to hijack the authentication of unspecified victims via features such as send message and change preferences, related to (1) functions/mailbox_display.php, (2) src/addrbook_search_html.php, (3) src/addressbook.php, (4) src/compose.php, (5) src/folders.php, (6) src/folders_create.php, (7) src/folders_delete.php, (8) src/folders_rename_do.php, (9) src/folders_rename_getname.php, (10) src/folders_subscribe.php, (11) src/move_messages.php, (12) src/options.php, (13) src/options_highlight.php, (14) src/options_identities.php, (15) src/options_order.php, (16) src/search.php, and (17) src/vcard.php.