Bernd Edlinger

The POLY1305 MAC implementation in OpenSSL contains a bug that might corrupt the internal state of applications on the Windows 64 platform when running on newer X86 64 processors supporting the AVX512-IFMA instructions. If an attacker can influence whether the POLY1305 MAC algorithm is used, the application state might be corrupted with various application-dependent consequences. The consequences of this kind of internal application state corruption can be various, from no consequences to the worst consequences, where the attacker could get complete control of the application process. However, given the contents of the registers are just zeroized, the most likely consequence would be an incorrect result of some application-dependent calculations or a crash leading to a denial of service.

The issue is related to the functions `DH check()`, `DH check ex()`, and `EVP PKEY param check()` in the OpenSSL library. These functions can cause excessive delays when checking excessively long DH keys or parameters, potentially leading to a Denial of Service attack if the key or parameters are obtained from an untrusted source. The `DH check()` function performs various checks on DH parameters, and a large `q` parameter value can trigger an overly long computation during some of these checks. The OpenSSL SSL/TLS implementation and the OpenSSL 3.0 and 3.1 FIPS providers are not affected by this issue.

O problema está relacionado a um bug de propagação de carry no procedimento de elevação ao quadrado MIPS32 e MIPS64 da biblioteca OpenSSL, o que pode levar ao comprometimento de algoritmos de curva elíptica, incluindo algumas das curvas padrão do TLS 1.3. Esse bug pode permitir que um invasor remoto divulgue informações protegidas, especialmente se chaves privadas forem reutilizadas. No entanto, os pré-requisitos para um ataque são considerados improváveis, e o impacto não foi analisado em detalhes. A quantidade de recursos necessários para tal ataque seria significativa.

O problema está relacionado ao tratamento incorreto da extensão TLS “signature algorithms cert”, o que pode causar uma desreferência de ponteiro NULL e levar a uma falha durante ou após um handshake TLS 1.3. Isso poderia ser explorado por um par mal-intencionado em um ataque de Negação de Serviço. A falha ocorre se um algoritmo de assinatura inválido ou não reconhecido for recebido do par.

The issue is related to a padding oracle attack in the `PKCS7 dataDecode` and `CMS decrypt set1 pkey` functions, allowing an attacker to recover a CMS/PKCS7 transported encryption key or decrypt any RSA encrypted message that was encrypted with the public RSA key. This can be achieved by sending a large number of messages to be decrypted. Applications using a certificate together with the private RSA key to select the correct recipient info to decrypt are not affected.