CVE-2023-0286

HIGH severity · CVSS 7.4 · CWE-843

7.4CVSS HIGH

Summary

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.

Impact & exploitability

Attack vectorNetwork

Attack complexityHigh

Privileges requiredNone

User interactionNone

Confidentiality impactHigh

Integrity impactNone

Availability impactHigh

Exploit probability (EPSS)88%

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H

Affected products we track (1)

OpenSSL

Recommendation

Apply the vendor fix promptly. Open any affected product above for its exact safe version.

Official patch: https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=2c6c9d439b484e1ba9830d8454a34fa4f80fdfe9 ↗

CVE-2023-0286

Summary

Impact & exploitability

Affected products we track (1)

Recommendation

Additional information