A timing side-channel issue was addressed with improvements to constant-time computation in cryptographic functions. This issue is fixed in macOS Sonoma 14.3, watchOS 10.3, tvOS 17.3, iOS 17.3 and iPadOS 17.3. An attacker may be able to decrypt legacy RSA PKCS#1 v1.5 ciphertexts without having the private key.
https://support.apple.com/kb/HT214085
https://support.apple.com/kb/HT214083
https://support.apple.com/kb/HT214082
https://support.apple.com/en-us/HT214061
https://support.apple.com/en-us/HT214060
https://support.apple.com/en-us/HT214059
https://support.apple.com/en-us/HT214055
http://seclists.org/fulldisclosure/2024/Mar/23
http://seclists.org/fulldisclosure/2024/Mar/22
http://seclists.org/fulldisclosure/2024/Jan/40
http://seclists.org/fulldisclosure/2024/Jan/39