CVE-2014-3568

OpenSSL anterior a 0.9.8zc, 1.0.0 anterior a 1.0.0o, y 1.0.1 anterior a 1.0.1j no fuerza correctamente la opción build no-ssl3, lo que permite a atacantes remotos evadir las restricciones de acceso a través de una negociación SSL 3.0, relacionado con s23_clnt.c y s23_srvr.c.

A flaw in the DTLS SRTP extension parsing code allows an attacker, who sends a carefully crafted handshake message, to cause OpenSSL to fail to free up to 64k of memory causing a memory leak. When an OpenSSL SSL/TLS/DTLS server receives a session ticket the integrity of that ticket is first verified. In the event of a session ticket integrity check failing, OpenSSL will fail to free memory causing a memory leak. The SSL protocol 3.0, as supported in OpenSSL and other products, supports CBC mode encryption where it could not adequately check the integrity of padding, because of the use of non-deterministic CBC padding. This protocol weakness makes it possible for an attacker to obtain clear text data through a padding-oracle attack. Some client applications (such as browsers) will reconnect using a downgraded protocol to work around interoperability bugs in older servers. This could be exploited by an active man-in-the-middle to downgrade connections to SSL 3.0 even if both sides of the connection support higher protocols. SSL 3.0 contains a number of weaknesses including POODLE.