An issue was discovered in Mbed TLS 3.5.x before 3.6.0. When an SSL context was reset with the mbedtls_ssl_session_reset() API, the maximum TLS version to be negotiated was not restored to the configured one. An attacker was able to prevent an Mbed TLS server from establishing any TLS 1.3 connection, potentially resulting in a Denial of Service or forced version downgrade from TLS 1.3 to TLS 1.2.

A vulnerability has been identified in APOGEE PXC Compact (BACnet) (All versions < V3.5.5), APOGEE PXC Compact (P2 Ethernet) (All versions < V2.8.20), APOGEE PXC Modular (BACnet) (All versions < V3.5.5), APOGEE PXC Modular (P2 Ethernet) (All versions < V2.8.20), Nucleus NET (All versions < V5.2), Nucleus ReadyStart V3 (All versions < V2012.12), Nucleus Source Code (All versions), PLUSCONTROL 1st Gen (All versions), TALON TC Compact (BACnet) (All versions < V3.5.5), TALON TC Modular (BACnet) (All versions < V3.5.5). Initial Sequence Numbers (ISNs) for TCP connections are derived from an insufficiently random source. As a result, the ISN of current and future TCP connections could be predictable. An attacker could hijack existing sessions or spoof future ones.

In Mbed TLS before 3.1.0, psa_aead_generate_nonce allows policy bypass or oracle-based decryption when the output buffer is at memory locations accessible to an untrusted application.

In Mbed TLS before 2.28.0 and 3.x before 3.1.0, psa_cipher_generate_iv and psa_cipher_encrypt allow policy bypass or oracle-based decryption when the output buffer is at memory locations accessible to an untrusted application.

Use of a Broken or Risky Cryptographic Algorithm in the function mbedtls_mpi_exp_mod() in lignum.c in Mbed TLS Mbed TLS all versions before 3.0.0, 2.27.0 or 2.16.11 allows attackers with access to precise enough timing and memory access information (typically an untrusted operating system attacking a secure enclave such as SGX or the TrustZone secure world) to recover the private keys used in RSA.

An exploitable free of a stack pointer vulnerability exists in the x509 certificate parsing code of ARM mbed TLS before 1.3.19, 2.x before 2.1.7, and 2.4.x before 2.4.2. A specially crafted x509 certificate, when parsed by mbed TLS library, can cause an invalid free of a stack pointer leading to a potential remote code execution. In order to exploit this vulnerability, an attacker can act as either a client or a server on a network to deliver malicious x509 certificates to vulnerable applications.

An issue was discovered in Mbed TLS 3.x before 3.6.1. With TLS 1.3, when a server enables optional authentication of the client, if the client-provided certificate does not have appropriate values in if keyUsage or extKeyUsage extensions, then the return value of mbedtls_ssl_get_verify_result() would incorrectly have the MBEDTLS_X509_BADCERT_KEY_USAGE and MBEDTLS_X509_BADCERT_KEY_USAGE bits clear. As a result, an attacker that had a certificate valid for uses other than TLS client authentication would nonetheless be able to use it for TLS client authentication. Only TLS 1.3 servers were affected, and only with optional authentication (with required authentication, the handshake would be aborted with a fatal alert).

ARM mbedTLS version 2.7.0 and earlier contains a Ciphersuite Allows Incorrectly Signed Certificates vulnerability in mbedtls_ssl_get_verify_result() that can result in ECDSA-signed certificates are accepted, when only RSA-signed ones should be.. This attack appear to be exploitable via Peers negotiate a TLS-ECDH-RSA-* ciphersuite. Any of the peers can then provide an ECDSA-signed certificate, when only an RSA-signed one should be accepted..

An issue was discovered in Mbed TLS before 2.24.0. The verification of X.509 certificates when matching the expected common name (the cn argument of mbedtls_x509_crt_verify) with the actual certificate name is mishandled: when the subjecAltName extension is present, the expected name is compared to any name in that extension regardless of its type. This means that an attacker could impersonate a 4-byte or 16-byte domain by getting a certificate for the corresponding IPv4 or IPv6 address (this would require the attacker to control that IP address, though).

An issue was discovered in Mbed TLS before 2.25.0 (and before 2.16.9 LTS and before 2.7.18 LTS). A NULL algorithm parameters entry looks identical to an array of REAL (size zero) and thus the certificate is considered valid. However, if the parameters do not match in any way, then the certificate should be considered invalid.

An issue was discovered in Arm Mbed TLS before 2.24.0. It incorrectly uses a revocationDate check when deciding whether to honor certificate revocation via a CRL. In some situations, an attacker can exploit this by changing the local clock.

An issue was discovered in Arm Mbed TLS before 2.16.6 and 2.7.x before 2.7.15. An attacker that can get precise enough side-channel measurements can recover the long-term ECDSA private key by (1) reconstructing the projective coordinate of the result of scalar multiplication by exploiting side channels in the conversion to affine coordinates; (2) using an attack described by Naccache, Smart, and Stern in 2003 to recover a few bits of the ephemeral scalar from those projective coordinates via several measurements; and (3) using a lattice attack to get from there to the long-term ECDSA private key used for the signatures. Typically an attacker would have sufficient access when attacking an SGX enclave and controlling the untrusted OS.

Issue summary: Use of -addreject option with the openssl x509 application adds a trusted use instead of a rejected use for a certificate. Impact summary: If a user intends to make a trusted certificate rejected for a particular use it will be instead marked as trusted for that use. A copy & paste error during minor refactoring of the code introduced this issue in the OpenSSL 3.5 version. If, for example, a trusted CA certificate should be trusted only for the purpose of authenticating TLS servers but not for CMS signature verification and the CMS signature verification is intended to be marked as rejected with the -addreject option, the resulting CA certificate will be trusted for CMS signature verification purpose instead. Only users which use the trusted certificate format who use the openssl x509 command line application to add rejected uses are affected by this issue. The issues affecting only the command line application are considered to be Low severity. The FIPS modules in 3.5, 3.4, 3.3, 3.2, 3.1 and 3.0 are not affected by this issue. OpenSSL 3.4, 3.3, 3.2, 3.1, 3.0, 1.1.1 and 1.0.2 are also not affected by this issue.