CVE-2016-6302

La función tls_decrypt_ticket en ssl/t1_lib.c en OpenSSL en versiones anteriores a 1.1.0 no considera el tamaño HMAC durante la validación de la longitud del ticket, lo que permite a atacantes remotos provocar una denegación de servicio a través de un ticket que es muy corto.

An integer underflow flaw leading to a buffer over-read was found in the way OpenSSL parsed TLS session tickets. A remote attacker could use this flaw to crash a TLS server using OpenSSL if it used SHA-512 as HMAC for session tickets.

USN-3087-1 fixed vulnerabilities in OpenSSL. The fix for CVE-2016-2182 was incomplete and caused a regression when parsing certificates. This update fixes the problem. Shi Lei discovered that OpenSSL incorrectly handled the OCSP Status Request extension. A remote attacker could possibly use this issue to cause memory consumption, resulting in a denial of service. Guido Vranken discovered that OpenSSL used undefined behaviour when performing pointer arithmetic. A remote attacker could possibly use this issue to cause OpenSSL to crash, resulting in a denial of service. This issue has only been addressed in Ubuntu 16.04 LTS in this update. CAsar Pereida, Billy Brumley, and Yuval Yarom discovered that OpenSSL did not properly use constant-time operations when performing DSA signing. A remote attacker could possibly use this issue to perform a cache-timing attack and recover private DSA keys. Quan Luo discovered that OpenSSL did not properly restrict the lifetime of queue entries in the DTLS implementation. A remote attacker could possibly use this issue to consume memory, resulting in a denial of service. Shi Lei discovered that OpenSSL incorrectly handled memory in the TS_OBJ_print_bio function. A remote attacker could possibly use this issue to cause a denial of service. It was discovered that the OpenSSL incorrectly handled the DTLS anti-replay feature. A remote attacker could possibly use this issue to cause a denial of service. Various other issues were also addressed.