جزئیات آسیب‌پذیری

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 of Service. For these reasons the issue was assessed as Low severity. The FIPS modules in 3.5, 3.4, 3.3 and 3.0 are not affected by this issue, as the TimeStamp Response implementation is outside the OpenSSL FIPS module boundary. OpenSSL 3.6, 3.5, 3.4, 3.3, 3.0 and 1.1.1 are vulnerable to this issue. OpenSSL 1.0.2 is not affected by this issue.

• https://openssl-library.org/news/secadv/20260127.txt vendor-advisory
• https://github.com/openssl/openssl/commit/a99349ebfc519999edc50620abe24d599b9eb085 patch
• https://github.com/openssl/openssl/commit/564fd9c73787f25693bf9e75faf7bf6bb1305d4e patch
• https://github.com/openssl/openssl/commit/27c7012c91cc986a598d7540f3079dfde2416eb9 patch
• https://github.com/openssl/openssl/commit/5eb0770ffcf11b785cf374ff3c19196245e54f1b patch
• https://github.com/openssl/openssl/commit/4e254b48ad93cc092be3dd62d97015f33f73133a patch
• https://cert-portal.siemens.com/productcert/html/ssa-265688.html