CVE-2022-1434: 
Rust vulnerability analysis and mitigation

CVE-2022-1434 is a low severity vulnerability discovered in OpenSSL 3.0's implementation of the RC4-MD5 ciphersuite, disclosed on May 3, 2022. The vulnerability affects OpenSSL versions 3.0.0 through 3.0.2, where the implementation incorrectly uses the AAD data as the MAC key, making it trivially predictable. This vulnerability was fixed in OpenSSL 3.0.3 (OpenSSL Advisory).

The vulnerability stems from an implementation flaw where the RC4-MD5 ciphersuite incorrectly uses the AAD (Additional Authenticated Data) as the MAC key. The issue has a CVSS v3.1 base score of 5.9 (Medium) with vector CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N. The vulnerability only manifests when specific conditions are met, including: OpenSSL must be compiled with enable-weak-ssl-ciphers option, the legacy provider must be explicitly loaded, the ciphersuite must be explicitly added to the list, the libssl security level must be set to 0, and a pre-TLSv1.3 version must be negotiated (NVD).

An attacker exploiting this vulnerability could perform a man-in-the-middle attack to modify data being sent between endpoints. If both endpoints are OpenSSL 3.0, the attacker could modify data in both directions. The confidentiality of data is not impacted - attackers cannot decrypt the data but can only modify it. The vulnerability also causes connection failures between OpenSSL 3.0 and non-OpenSSL 3.0 endpoints when using this ciphersuite (OpenSSL Advisory).

The primary mitigation is to upgrade to OpenSSL version 3.0.3 or later. For systems that cannot be immediately upgraded, the vulnerability can be mitigated by ensuring that RC4-MD5 ciphersuite is not enabled, maintaining the default security level (1), and not explicitly loading the legacy provider (OpenSSL Advisory).