Source: mbedtls Version: 3.6.3-1 Severity: important Tags: security upstream X-Debbugs-Cc: car...@debian.org, Debian Security Team <t...@security.debian.org>
Hi, The following vulnerability was published for mbedtls. CVE-2025-49600[0]: | 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. If you fix the vulnerability please also make sure to include the CVE (Common Vulnerabilities & Exposures) id in your changelog entry. For further information see: [0] https://security-tracker.debian.org/tracker/CVE-2025-49600 https://www.cve.org/CVERecord?id=CVE-2025-49600 [1] https://github.com/Mbed-TLS/mbedtls-docs/blob/main/security-advisories/mbedtls-security-advisory-2025-06-3.md Please adjust the affected versions in the BTS as needed. Regards, Salvatore
