CVE-2023-0286

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.