The do_change_cipher_spec function in OpenSSL 0.9.6c to 0.9.6k, and 0.9.7a to 0.9.7c, allows remote attackers to cause a denial of service (crash) via a crafted SSL/TLS handshake that triggers a null dereference.
OpenSSL 0.9.6 before 0.9.6d does not properly handle unknown message types, which allows remote attackers to cause a denial of service (infinite loop), as demonstrated using the Codenomicon TLS Test Tool.
The SSL/TLS handshaking code in OpenSSL 0.9.7a, 0.9.7b, and 0.9.7c, when using Kerberos ciphersuites, does not properly check the length of Kerberos tickets during a handshake, which allows remote attackers to cause a denial of service (crash) via a crafted SSL/TLS handshake that causes an out-of-bounds read.
Buffer overflow in the ISAKMP functionality for Check Point VPN-1 and FireWall-1 NG products, before VPN-1/FireWall-1 R55 HFA-03, R54 HFA-410 and NG FP3 HFA-325, or VPN-1 SecuRemote/SecureClient R56, may allow remote attackers to execute arbitrary code during VPN tunnel negotiation.