s2n uses a predictable IV for CBC-mode cipher suites backed by OpenSSL composite ciphers with TLS versions 1.1 and 1.2. This may allow adaptive chosen-plaintext attacks against s2n servers running on hosts supporting AES-NI. s2n default security policies list CBC-mode ciphers as the last option.
Customers of AWS services do not need to take action. s2n users and AWS customers should update client applications to the most recent version.
All versions of s2n from commit b3721cb to 0df8de3 and built with OpenSSL are affected by this issue.
Affected s2n users should fetch s2n commit b74b955 or build s2n with an alternative cryptographic library.
s2n uses a predictable IV for CBC-mode cipher suites backed by OpenSSL composite ciphers with TLS versions 1.1 and 1.2. This may allow adaptive chosen-plaintext attacks against s2n servers running on hosts supporting AES-NI. s2n default security policies list CBC-mode ciphers as the last option.
Customers of AWS services do not need to take action. s2n users and AWS customers should update client applications to the most recent version.
All versions of s2n from commit b3721cb to 0df8de3 and built with OpenSSL are affected by this issue.
Affected s2n users should fetch s2n commit b74b955 or build s2n with an alternative cryptographic library.