Botan is a C++ cryptography library. Prior to version 3.11.0, during processing of an X.509 certificate path using name constraints which restrict the set of allowable DNS names, if no subject alternative name is defined in the end-entity certificate Botan would check that the CN was allowed by the DNS name constraints, even though this check is technically not required by RFC 5280. However this check failed to account for the possibility of a mixed-case CN. Thus a certificate with CN=Sub.EVIL.COM and no subject alternative name would bypasses an excludedSubtrees constraint for evil.com because the comparison is case-sensitive. This issue has been patched in version 3.11.0.
Botan is a C++ cryptography library. From version 2.3.0 to before version 3.11.0, during SM2 decryption, the code that checked the authentication code value (C3) failed to check that the encoded value was of the expected length prior to comparison. An invalid ciphertext can cause a heap over-read of up to 31 bytes, resulting in a crash or potentially other undefined behavior. This issue has been patched in version 3.11.0.
Botan before 3.6.0, when certain LLVM versions are used, has compiler-induced secret-dependent control flow in lib/utils/ghash/ghash.cpp in GHASH in AES-GCM. There is a branch instead of an XOR with carry. This was observed for Clang in LLVM 15 on RISC-V.
Botan before 3.6.0, when certain GCC versions are used, has a compiler-induced secret-dependent operation in lib/utils/donna128.h in donna128 (used in Chacha-Poly1305 and x25519). An addition can be skipped if a carry is not set. This was observed for GCC 11.3.0 with -O2 on MIPS, and GCC on x86-i386. (Only 32-bit processors can be affected.)