Upstream information

CVE-2025-49600 at MITRE

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.

SUSE information

Overall state of this security issue: Does not affect SUSE products

This issue is currently rated as having moderate severity.

CVSS v3 Scores
  CNA (MITRE)
Base Score 4.9
Vector CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N
Attack Vector Physical
Attack Complexity High
Privileges Required None
User Interaction None
Scope Changed
Confidentiality Impact None
Integrity Impact High
Availability Impact None
CVSSv3 Version 3.1
SUSE Bugzilla entry: 1245808 [NEW]

No SUSE Security Announcements cross referenced.


SUSE Timeline for this CVE

CVE page created: Fri Jul 4 18:00:55 2025
CVE page last modified: Mon Jul 7 12:42:09 2025