CVE-2025-49600 Information
Description
In MbedTLS 3.3.0 before 3.6.4 mbedtls_lms_verify may accept invalid signatures if hash computation fails and internal errors go unchecked enabling LMS (Leighton-Micali Signature) forgery in a fault scenario. Specifically unchecked return values in mbedtls_lms_verify allow an attacker (who can induce a hardware hash accelerator fault) to bypass LMS signature verification by reusing stale stack data resulting in acceptance of an invalid signature. In mbedtls_lms_verify the return values of the internal Merkle tree functions create_merkle_leaf_value and create_merkle_internal_value are not checked. These functions return an integer that indicates whether the call succeeded or not. If a failure occurs the output buffer (Tc_candidate_root_node) may remain uninitialized and the result of the signature verification is unpredictable. When the software implementation of SHA-256 is used these functions will not fail. However with hardware-accelerated hashing an attacker could use fault injection against the accelerator to bypass verification.
Reference
Related CNNVD
CNNVD-202507-492 (Published: 2025-07-04)
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