Executive brief
The rust-openssl library, which provides cryptographic tools for the Rust programming language, contains a memory management flaw. When using specific encryption methods (AES key-wrap-with-padding), the library may miscalculate the required memory space, leading to a crash or potential data corruption. This could allow an attacker with local access to disrupt services or potentially manipulate application data.
Technical details
A heap-based buffer overflow exists in rust-openssl's CipherCtxRef::cipher_update, CipherCtxRef::cipher_update_vec, and symm::Crypter::update functions. The root cause is an incorrect calculation of the required output buffer size when using AES key-wrap-with-padding ciphers (EVP_aes_{128,192,256}_wrap_pad). If the input length is not a multiple of 8 bytes, the underlying OpenSSL implementation may write up to 7 bytes beyond the allocated buffer. An attacker who can influence the length of the plaintext being encrypted can trigger this overflow to cause heap corruption. The vulnerability is fixed in version 0.10.79.
Affected products
- rust-openssl openssl (rust-openssl) >= 0.10.0, < 0.10.79
Timeline
- 2026-05-04: disclosed: Initial disclosure by maintainers
- 2026-05-07: advisory: GitHub Advisory published
- 2026-05-14: advisory: NVD entry published