zetacomponents/Mail

In Claws Mail 3.14.1, 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.

The send function in the ezcMailMtaTransport class in Zeta Components Mail before 1.8.2 does not properly restrict the set of characters used in the ezcMail returnPath property, which might allow remote attackers to execute arbitrary code via a crafted email address, as demonstrated by one containing "-X/path/to/wwwroot/file.php."

The mail gem before 2.5.5 for Ruby (aka A Really Ruby Mail Library) is vulnerable to SMTP command injection via CRLF sequences in a RCPT TO or MAIL FROM command, as demonstrated by CRLF sequences immediately before and after a DATA substring.