CVE-2023-0286

Published: 7 February 2023

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.

Status

Severity score breakdown

References

• https://www.openssl.org/news/secadv/20230207.txt
• https://ubuntu.com/security/notices/USN-5844-1
• https://ubuntu.com/security/notices/USN-5845-1
• https://ubuntu.com/security/notices/USN-5845-2
• https://ubuntu.com/security/notices/USN-6564-1
• https://www.cve.org/CVERecord?id=CVE-2023-0286
• NVD
• Launchpad
• Debian