A Lucky 13 timing side channel in mbedtls_ssl_decrypt_buf in library/ssl_msg.c in Trusted Firmware Mbed TLS through 2.23.0 allows an attacker to recover secret key information. This affects CBC mode because of a computed time difference based on a padding length.

References

• https://nvd.nist.gov/vuln/detail/CVE-2020-16150
• https://lists.fedoraproject.org/archives/list/[email protected]/message/5OSOFUD6UTGTDDSQRS62BPXDU52I6PUA/
• https://lists.fedoraproject.org/archives/list/[email protected]/message/IRPBHCQKZXHVKOP5O5EWE7P76AWGUXQJ/
• https://lists.fedoraproject.org/archives/list/[email protected]/message/OD3NM6GD73CTFFRBKG5G2ACXGG7QQHCC/
• https://tls.mbed.org/tech-updates/security-advisories
• https://tls.mbed.org/tech-updates/security-advisories/mbedtls-security-advisory-2020-09-1
• https://lists.debian.org/debian-lts-announce/2022/12/msg00036.html
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5OSOFUD6UTGTDDSQRS62BPXDU52I6PUA/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IRPBHCQKZXHVKOP5O5EWE7P76AWGUXQJ/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OD3NM6GD73CTFFRBKG5G2ACXGG7QQHCC/