CVE Catalog

CVE-2023-0286

HighCVSS 7.4
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Very high risk
61.98%

99th percentile - higher than 99% of all known CVEs

Summary

There is a type confusion vulnerability in OpenSSL relating to X.400 address processing inside an X.509 GeneralName. X.400 addresses are parsed as an ASN1_STRING, but the public structure definition for GENERAL_NAME incorrectly specifies the x400Address field as ASN1_TYPE, which is then interpreted by GENERAL_NAME_cmp as an ASN1_TYPE rather than an ASN1_STRING. When CRL checking is enabled (X509_V_FLAG_CRL_CHECK), an attacker may pass arbitrary pointers to a memcmp call, enabling memory reads or denial of service.

Risk Assessment

Applications using CRL checking may be exposed to memory reads or denial of service, potentially leading to data leakage or service unavailability.

Recommendation

Update OpenSSL to a version containing the fix; if updating is not possible, consider disabling CRL checking unless it is required.

Other vulnerabilities in OpenSSL

See all
Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS