The vulnerability exists in rust‑openssl versions 0.10.0 through 0.10.78, where the cipher update functions incorrectly size the output buffer for AES key‑wrap‑with‑padding ciphers. For plaintext lengths that are not a multiple of eight, OpenSSL writes up to seven bytes beyond the caller’s buffer. This results in attacker‑controllable heap corruption, which can be leveraged to alter memory and potentially achieve remote code execution. The weakness is a classic buffer overflow (CWE‑122).

Affected are users of the rust‑openssl library, specifically those employing AES key‑wrap‑with‑padding ciphers (EVP_aes_128_wrap_pad, EVP_aes_192_wrap_pad, or EVP_aes_256_wrap_pad) in library versions 0.10.0 to 0.10.78. The issue does not affect later releases, such as 0.10.79 and beyond.

The CVSS score for this issue is 5.1, indicating moderate severity. The EPSS score is not available, and the vulnerability is not listed in CISA KEV, suggesting no known widespread exploitation yet. The likely attack vector requires the attacker to supply a plaintext of non‑multiple‑of‑eight length to a key‑wrap‑with‑padding operation, which is user‑controlled, so the flaw can be triggered by a remote or local application that processes attacker‑supplied data.