Executive brief
wolfProvider is a cryptographic module used to secure TLS and DTLS communications. A flaw causes the same encryption key and nonce to be reused for every record within a connection, which allows attackers to recover unencrypted message content and forge authentication tags, compromising both confidentiality and integrity of encrypted communications.
Technical details
wolfProvider contains a cryptographic nonce generation flaw in AES-GCM mode for TLS 1.2 and DTLS 1.2. The 8-byte explicit nonce is generated once when the TLS write key is established and is never incremented for subsequent records, causing every encrypted record within a connection to use an identical key-nonce pair. Reusing GCM key-nonce pairs violates the cryptographic guarantee of authenticated encryption: XORing two ciphertexts encrypted under the same key and nonce recovers the XOR of their plaintexts (known-plaintext recovery), and the GHASH authentication key is leaked, enabling forgery of authentication tags. The vulnerability requires a network-reachable TLS/DTLS 1.2 connection with AES-GCM cipher negotiation. AES-CCM, TLS 1.3, and non-TLS uses of the cipher are unaffected. Fixed in wolfProvider 1.2.2.
Affected products
- wolfSSL wolfProvider before 1.2.2
Timeline
- 2026-08-28: disclosed