CVE-2025-69420

/// Technical description

Issue summary: A type confusion vulnerability exists in the TimeStamp Response

verification code where an ASN1_TYPE union member is accessed without first

validating the type, causing an invalid or NULL pointer dereference when

processing a malformed TimeStamp Response file.

Impact summary: An application calling TS_RESP_verify_response() with a

malformed TimeStamp Response can be caused to dereference an invalid or

NULL pointer when reading, resulting in a Denial of Service.

The functions ossl_ess_get_signing_cert() and ossl_ess_get_signing_cert_v2()

access the signing cert attribute value without validating its type.

When the type is not V_ASN1_SEQUENCE, this results in accessing invalid memory

through the ASN1_TYPE union, causing a crash.

Exploiting this vulnerability requires an attacker to provide a malformed

TimeStamp Response to an application that verifies timestamp responses. The

TimeStamp protocol (RFC 3161) is not widely used and the impact of the

exploit is just a Denial

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References