An issue was discovered in Roundcube Webmail before 1.4.4. A CSRF attack can cause an authenticated user to be logged out because POST was not considered.

Roundcube Webmail through 1.3.9 mishandles Punycode xn-- domain names, leading to homograph attacks.

In Roundcube Webmail before 1.3.10, an attacker in possession of S/MIME or PGP encrypted emails can wrap them as sub-parts within a crafted multipart email. The encrypted part(s) can further be hidden using HTML/CSS or ASCII newline characters. This modified multipart email can be re-sent by the attacker to the intended receiver. If the receiver replies to this (benign looking) email, they unknowingly leak the plaintext of the encrypted message part(s) back to the attacker.

Roundcube before 1.3.7 mishandles GnuPG MDC integrity-protection warnings, which makes it easier for attackers to obtain sensitive information, a related issue to CVE-2017-17688. This is associated with plugins/enigma/lib/enigma_driver_gnupg.php.

steps/mail/func.inc in Roundcube before 1.3.8 has XSS via crafted use of <svg><style>, as demonstrated by an onload attribute in a BODY element, within an HTML attachment.

The OpenPGP specification allows a Cipher Feedback Mode (CFB) malleability-gadget attack that can indirectly lead to plaintext exfiltration, aka EFAIL. NOTE: third parties report that this is a problem in applications that mishandle the Modification Detection Code (MDC) feature or accept an obsolete packet type, not a problem in the OpenPGP specification

In Roundcube from versions 1.2.0 to 1.3.5, with the archive plugin enabled and configured, it's possible to exploit the unsanitized, user-controlled "_uid" parameter (in an archive.php _task=mail&_mbox=INBOX&_action=plugin.move2archive request) to perform an MX (IMAP) injection attack by placing an IMAP command after a %0d%0a sequence. NOTE: this is less easily exploitable in 1.3.4 and later because of a Same Origin Policy protection mechanism.

roundcube version 1.3.4 and earlier contains an Insecure Permissions vulnerability in enigma plugin that can result in exfiltration of gpg private key. This attack appear to be exploitable via network connectivity.

Roundcube Webmail before 1.1.10, 1.2.x before 1.2.7, and 1.3.x before 1.3.3 allows unauthorized access to arbitrary files on the host's filesystem, including configuration files, as exploited in the wild in November 2017. The attacker must be able to authenticate at the target system with a valid username/password as the attack requires an active session. The issue is related to file-based attachment plugins and _task=settings&_action=upload-display&_from=timezone requests.

program/steps/addressbook/photo.inc in Roundcube Webmail before 1.0.6 and 1.1.x before 1.1.2 allows remote authenticated users to read arbitrary files via the _alt parameter when uploading a vCard.