There is a type confusion vulnerability relating to X.400 address processing inside an X.509 GeneralName. X.400 addresses were parsed as an ASN1_STRING but the public structure definition for GENERAL_NAME incorrectly specified the type of the x400Address field as ASN1_TYPE. This field is subsequently interpreted by the OpenSSL function GENERAL_NAME_cmp as an ASN1_TYPE rather than an ASN1_STRING. When CRL checking is enabled (i.e. the application sets the X509_V_FLAG_CRL_CHECK flag), this vulnerability may allow an attacker to pass arbitrary pointers to a memcmp call, enabling them to read memory contents or enact a denial of service. In most cases, the attack requires the attacker to provide both the certificate chain and CRL, neither of which need to have a valid signature. If the attacker only controls one of these inputs, the other input must already contain an X.400 address as a CRL distribution point, which is uncommon. As such, this vulnerability is most likely to only affect applications which have implemented their own functionality for retrieving CRLs over a network. Found by David Benjamin (Google). Fix developed by Hugo Landau.
Aliases: CVE-2023-0286
Modified: 2023-04-03T01:17:00.600Z
Published: 2023-04-03T02:22:58.600Z
References
https://www.openssl.org/news/vulnerabilities.html#CVE-2023-0286
https://github.com/MidnightBSD/src/commit/fae47427305375221e4e8d49f1027c53e8770430