TCP, when using a large Window Size, makes it easier for remote attackers to guess sequence numbers and cause a denial of service (connection loss) to persistent TCP connections by repeatedly injecting a TCP RST packet, especially in protocols that use long-lived connections, such as BGP.

PGP Corporate Desktop before 7.1, Personal Security before 7.0.3, Freeware before 7.0.3, and E-Business Server before 7.1 does not properly display when invalid userID's are used to sign a message, which could allow an attacker to make the user believe that the document has been signed by a trusted third party by adding a second, invalid user ID to a key which has already been signed by the third party, aka the "PGPsdk Key Validity Vulnerability."

ASCII Armor parser in Windows PGP 7.0.3 and earlier allows attackers to create files in arbitrary locations via a malformed ASCII armored file.

PGP 5.5.x through 6.5.3 does not properly check if an Additional Decryption Key (ADK) is stored in the signed portion of a public certificate, which allows an attacker who can modify a victim's public certificate to decrypt any data that has been encrypted with the modified certificate.

The pgpk command in PGP 5.x on Unix systems uses an insufficiently random data source for non-interactive key pair generation, which may produce predictable keys.