Pine before version 4.21 does not properly filter shell metacharacters from URLs, which allows remote attackers to execute arbitrary commands via a malformed URL.

The c-client library in Internet Message Access Protocol (IMAP) dated before 2002 RC2, as used by Pine 4.20 through 4.44, allows remote attackers to cause a denial of service (client crash) via a MIME-encoded email with Content-Type header containing an empty boundary field.

Buffer overflow in the automatic mail checking component of Pine 4.21 and earlier allows remote attackers to execute arbitrary commands via a long From: header.

Buffer overflow in University of Washington c-client library (used by pine and other programs) allows remote attackers to execute arbitrary commands via a long X-Keywords header.

Integer signedness error in rfc2231getparam from strings.c in PINE before 4.58 allows remote attackers to execute arbitrary code via an email that causes an out-of-bounds array access using a negative number.

Buffer overflow in PINE before 4.58 allows remote attackers to execute arbitrary code via a malformed message/external-body MIME type.

URL-handling code in Pine 4.43 and earlier allows remote attackers to execute arbitrary commands via a URL enclosed in single quotes and containing shell metacharacters (&).

Pine 4.44 and earlier allows remote attackers to cause a denial of service (core dump and failed restart) via an email message with a From header that contains a large number of quotation marks (").

Pine 4.2.1 through 4.4.4 puts Unix usernames and/or uid into Sender: and X-Sender: headers, which could allow remote attackers to obtain sensitive information.