The email gateway in RT (aka Request Tracker) 3.0.0 through 4.x before 4.0.23 and 4.2.x before 4.2.10 allows remote attackers to cause a denial of service (CPU and disk consumption) via a crafted email.

Best Practical Solutions RT 3.8.x before 3.8.15 and 4.0.x before 4.0.8, when GnuPG is enabled, does not ensure that the UI labels unencrypted messages as unencrypted, which might make it easier for remote attackers to spoof details of a message's origin or interfere with encryption-policy auditing via an e-mail message to a queue's address.

Best Practical Solutions RT 3.8.x before 3.8.15 and 4.0.x before 4.0.8, when GnuPG is enabled, allows remote attackers to configure encryption or signing for certain outbound e-mail, and possibly cause a denial of service (loss of e-mail readability), via an e-mail message to a queue's address.

Best Practical Solutions RT 3.8.x before 3.8.15 and 4.0.x before 4.0.8, when GnuPG is enabled with a "Sign by default" queue configuration, uses a queue's key for signing, which might allow remote attackers to spoof messages by leveraging the lack of authentication semantics.

Best Practical Solutions RT 3.8.x before 3.8.15 and 4.0.x before 4.0.8, when GnuPG is enabled, allows remote attackers to bypass intended restrictions on reading keys in the product's keyring, and trigger outbound e-mail messages signed by an arbitrary stored secret key, by leveraging a UI e-mail signing privilege.

SQL injection vulnerability in Approvals/ in Request Tracker (RT) 4.0.10 and earlier allows remote attackers to execute arbitrary SQL commands via the ShowPending parameter. NOTE: the vendor disputes this issue, stating "We were unable to replicate it, and the individual that reported it retracted their report," and "we had verified that the claimed exploit did not function according to the author's claims.