CVE-2023-0286

There is a type confusion vulnerability relating to X.400 address processing<br /> inside an X.509 GeneralName. X.400 addresses were parsed as an ASN1_STRING but<br /> the public structure definition for GENERAL_NAME incorrectly specified the type<br /> of the x400Address field as ASN1_TYPE. This field is subsequently interpreted by<br /> the OpenSSL function GENERAL_NAME_cmp as an ASN1_TYPE rather than an<br /> ASN1_STRING.<br /> <br /> When CRL checking is enabled (i.e. the application sets the<br /> X509_V_FLAG_CRL_CHECK flag), this vulnerability may allow an attacker to pass<br /> arbitrary pointers to a memcmp call, enabling them to read memory contents or<br /> enact a denial of service. In most cases, the attack requires the attacker to<br /> provide both the certificate chain and CRL, neither of which need to have a<br /> valid signature. If the attacker only controls one of these inputs, the other<br /> input must already contain an X.400 address as a CRL distribution point, which<br /> is uncommon. As such, this vulnerability is most likely to only affect<br /> applications which have implemented their own functionality for retrieving CRLs<br /> over a network.