Botan is a C++ cryptography library. Prior to version 3.11.1, the TLS 1.3 implementation allowed ApplicationData records to be processed prior to the Finished message being received. A server which is attempting to enforce client authentication via certificates can by bypassed by a client which entirely omits Certificate, CertificateVerify, and the Finished message and instead sends application data records. This vulnerability is fixed in 3.11.1.

Botan is a C++ cryptography library. In 3.11.0, the function CertificateStore::certificateknown had a misleading name; it would return true if any certificate in the store had a DN (and subject key identifier, if set) matching that of the argument. It did not check that the cert it found and the cert it was passed were actually the same certificate. In 3.11.0 an extension of path validation logic was made which assumed that certificateknown only returned true if the certificates were in fact identical. The impact is that if an end entity certificate is presented, and its DN (and subject key identifier, if set) match that of any trusted root, the end entity certificate is accepted immediately as if it itself were a trusted root. , This vulnerability is fixed in 3.11.1.

In Botan before 2.19.3, it is possible to forge OCSP responses due to a certificate verification error. This issue was introduced in Botan 1.11.34 (November 2016).

The ElGamal implementation in Botan through 2.18.1, as used in Thunderbird and other products, allows plaintext recovery because, during interaction between two cryptographic libraries, a certain dangerous combination of the prime defined by the receiver's public key, the generator defined by the receiver's public key, and the sender's ephemeral exponents can lead to a cross-configuration attack against OpenPGP.

An issue was discovered in Botan 1.11.32 through 2.x before 2.6.0. An off-by-one error when processing malformed TLS-CBC ciphertext could cause the receiving side to include in the HMAC computation exactly 64K bytes of data following the record buffer, aka an over-read. The MAC comparison will subsequently fail and the connection will be closed. This could be used for denial of service. No information leak occurs.

Botan 2.2.0 - 2.4.0 (fixed in 2.5.0) improperly handled wildcard certificates and could accept certain certificates as valid for hostnames when, under RFC 6125 rules, they should not match. This only affects certificates issued to the same domain as the host, so to impersonate a host one must already have a wildcard certificate matching other hosts in the same domain. For example, b.example.com would match some hostnames that do not begin with a 'b' character.

Botan is a C++ cryptography library. Prior to 3.12.0, certain patterns of indefinite length encodings in BER data could cause quadratic behavior in the parser, resulting in a denial of service. Such BER encodings were accepted even in structures which are required to be encoded as DER, which prohibits indefinite length encodings. This vulnerability is fixed in 3.12.0.

In Botan 1.8.0 through 1.11.33, when decoding BER data an integer overflow could occur, which would cause an incorrect length field to be computed. Some API callers may use the returned (incorrect and attacker controlled) length field in a way which later causes memory corruption or other failure.

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 is a C++ cryptography library. From version 3.0.0 to before version 3.11.0, during X509 path validation, OCSP responses were checked for an appropriate status code, but critically omitted verifying the signature of the OCSP response itself. This issue has been patched in version 3.11.0.

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 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.)

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 is a C++ cryptography library. X.509 certificates can identify elliptic curves using either an object identifier or using explicit encoding of the parameters. A bug in the parsing of name constraint extensions in X.509 certificates meant that if the extension included both permitted subtrees and excluded subtrees, only the permitted subtree would be checked. If a certificate included a name which was permitted by the permitted subtree but also excluded by excluded subtree, it would be accepted. Fixed in versions 3.5.0 and 2.19.5.

bcrypt password hashing in Botan before 2.1.0 does not correctly handle passwords with a length between 57 and 72 characters, which makes it easier for attackers to determine the cleartext password.

The Miller-Rabin primality check in Botan before 1.10.8 and 1.11.x before 1.11.9 improperly uses a single random base, which makes it easier for remote attackers to defeat cryptographic protection mechanisms via a DH group.

botan 1.11.x before 1.11.22 improperly handles wildcard matching against hostnames, which might allow remote attackers to have unspecified impact via a valid X.509 certificate, as demonstrated by accepting .example.com as a match for bar.foo.example.com.

botan before 1.11.22 improperly validates certificate paths, which allows remote attackers to cause a denial of service (infinite loop and memory consumption) via a certificate with a loop in the certificate chain.

A padding oracle attack was possible against TLS CBC ciphersuites because if a certain length check on the packet fields failed, a different alert type than one used for message authentication failure would be returned to the sender. This check triggering would leak information about the value of the padding bytes and could be used to perform iterative decryption.

As with most such oracle attacks, the danger depends on the underlying protocol - HTTP servers are particularly vulnerable. The current analysis suggests that to exploit it an attacker would first have to guess several bytes of plaintext, but again this is quite possible in many situations including HTTP.

External references:

http://botan.randombit.net/security.html

Botan before 1.10.13 and 1.11.x before 1.11.22 make it easier for remote attackers to conduct million-message attacks by measuring time differences, related to decoding of PKCS#1 padding.

The BER decoder in Botan 1.10.x before 1.10.10 and 1.11.x before 1.11.19 allows remote attackers to cause a denial of service (memory consumption) via unspecified vectors, related to a length field.

The BER decoder in Botan 0.10.x before 1.10.10 and 1.11.x before 1.11.19 allows remote attackers to cause a denial of service (application crash) via an empty BIT STRING in ASN.1 data.

In Botan 1.11.29 through 1.11.32, RSA decryption with certain padding options had a detectable timing channel which could given sufficient queries be used to recover plaintext, aka an "OAEP side channel" attack.

The Curve25519 code in botan before 1.11.31, on systems without a native 128-bit integer type, might allow attackers to have unspecified impact via vectors related to undefined behavior, as demonstrated on 32-bit ARM systems compiled by Clang.

The X509Certificate::allowedusage function in botan 1.11.x before 1.11.31 might allow attackers to have unspecified impact by leveraging a call with more than one KeyUsage set in the enum value.

Botan before 1.10.13 and 1.11.x before 1.11.29 do not use a constant-time algorithm to perform a modular inverse on the signature nonce k, which might allow remote attackers to obtain ECDSA secret keys via a timing side-channel attack.

Botan 1.11.x before 1.11.29 does not enforce TLS policy for (1) signature algorithms and (2) ECC curves, which allows remote attackers to conduct downgrade attacks via unspecified vectors.

Heap-based buffer overflow in the P-521 reduction function in Botan 1.11.x before 1.11.27 allows remote attackers to cause a denial of service (memory overwrite and crash) or execute arbitrary code via unspecified vectors.

The ressol function in Botan before 1.10.11 and 1.11.x before 1.11.27 allows remote attackers to cause a denial of service (infinite loop) via unspecified input to the OS2ECP function, related to a composite modulus.

Integer overflow in the PointGFp constructor in Botan before 1.10.11 and 1.11.x before 1.11.27 allows remote attackers to overwrite memory and possibly execute arbitrary code via a crafted ECC point, which triggers a heap-based buffer overflow.