CVE-2014-3572 in MacOS X
Summary
by MITRE
The ssl3_get_key_exchange function in s3_clnt.c in OpenSSL before 0.9.8zd, 1.0.0 before 1.0.0p, and 1.0.1 before 1.0.1k allows remote SSL servers to conduct ECDHE-to-ECDH downgrade attacks and trigger a loss of forward secrecy by omitting the ServerKeyExchange message.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 09/22/2022
The vulnerability described in CVE-2014-3572 represents a critical weakness in OpenSSL's SSL/TLS implementation that specifically affects the key exchange process during SSL handshakes. This issue impacts multiple OpenSSL versions including 0.9.8 series before 0.9.8zd, 1.0.0 series before 1.0.0p, and 1.0.1 series before 1.0.1k. The flaw occurs within the ssl3_get_key_exchange function located in s3_clnt.c, which is responsible for processing key exchange messages from SSL servers during the client-side handshake process. This vulnerability enables malicious actors to perform protocol downgrade attacks that compromise the security guarantees typically provided by modern cryptographic implementations.
The technical flaw stems from OpenSSL's improper handling of the ServerKeyExchange message in certain ECDHE (Elliptic Curve Diffie-Hellman Ephemeral) key exchange scenarios. When an SSL server omits sending the ServerKeyExchange message during the handshake process, the client fails to properly validate this omission and continues with a less secure key exchange mechanism. This behavior allows attackers to force the use of weaker cryptographic parameters, effectively downgrading the security level of the connection. The vulnerability specifically targets the transition from ECDHE to ECDH (Elliptic Curve Diffie-Hellman) key exchange methods, which are fundamental to establishing secure communications and maintaining forward secrecy in TLS connections.
The operational impact of this vulnerability is severe as it directly undermines the forward secrecy property that is essential for protecting encrypted communications. Forward secrecy ensures that even if long-term cryptographic keys are compromised in the future, previously intercepted communications remain secure. When this vulnerability is exploited, attackers can successfully downgrade connections to use less secure key exchange mechanisms that do not provide the same level of protection against future key compromises. This makes the vulnerability particularly dangerous in environments where sensitive data is transmitted and stored, as it allows attackers to potentially recover plaintext communications that should remain protected.
This vulnerability maps to CWE-327, which addresses the use of weak cryptographic algorithms, and is related to the broader category of cryptographic weakness patterns that affect TLS implementations. From an ATT&CK framework perspective, this vulnerability aligns with the T1573.002 technique for "Encrypted Channels" and represents a protocol-level attack that can be leveraged to weaken the security posture of affected systems. The attack vector requires a man-in-the-middle position where an attacker can intercept and modify SSL/TLS handshakes, making it particularly relevant to network security monitoring and intrusion detection systems that should be configured to detect such anomalous handshake behaviors. Organizations should implement immediate patches and updates to address this vulnerability, while also reviewing their cryptographic configurations to ensure proper enforcement of strong key exchange mechanisms and prevent downgrade attacks from occurring in their networks.