NULL dereference during PKCS7 data verification

CVE-2023-0401

Summary

A null pointer dereference occurs during the verification of PKCS7 signed or signedAndEnveloped data in OpenSSL. If the signature’s hash algorithm is recognized by the OpenSSL library but the necessary implementation of that algorithm is not available, the process fails during digest initialization. This situation arises often in cases where the FIPS-enabled configuration is used or when the legacy provider is not loaded. The absence of a proper check for the return value from the initialization function can lead to invalid usage of the digest API, which may result in a crash for third-party applications that rely on these functions for verifying signatures on untrusted data.

References