Bug 2376427 (CVE-2025-49601)

Summary: CVE-2025-49601 mbedtls: MbedTLS LMS Public Key Out-of-Bounds Read
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedKeywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in mbedtls. The `mbedtls_lms_import_public_key` function fails to validate input buffer size before reading a 32-bit field, potentially leading to an out-of-bounds read when processing truncated input. This flaw allows a network-based attacker to trigger this condition by providing a specially crafted public key file. This out-of-bounds read may result in an application-level denial of service.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2376706, 2376707, 2376708, 2376709, 2376710, 2382563    
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Description OSIDB Bzimport 2025-07-04 15:01:33 UTC 
In MbedTLS 3.3.0 before 3.6.4, mbedtls_lms_import_public_key does not check that the input buffer is at least 4 bytes before reading a 32-bit field, allowing a possible out-of-bounds read on truncated input. Specifically, an out-of-bounds read in mbedtls_lms_import_public_key allows context-dependent attackers to trigger a crash or limited adjacent-memory disclosure by supplying a truncated LMS (Leighton-Micali Signature) public-key buffer under four bytes. An LMS public key starts with a 4-byte type indicator. The function mbedtls_lms_import_public_key reads this type indicator before validating the size of its input.