[Debian-iot-maintainers] Bug#1108788: mbedtls: CVE-2025-49601: Out-of-bounds read in mbedtls_lms_import_public_key()

[Salvatore Bonaccorso]

Source: mbedtls
Version: 3.6.3-1
Severity: important
Tags: security upstream
X-Debbugs-Cc: carnil at debian.org, Debian Security Team <team at security.debian.org>

Hi,

The following vulnerability was published for mbedtls.

CVE-2025-49601[0]:
| 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.


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-2025-49601
    https://www.cve.org/CVERecord?id=CVE-2025-49601
[1] https://github.com/Mbed-TLS/mbedtls-docs/blob/main/security-advisories/mbedtls-security-advisory-2025-06-4.md

Please adjust the affected versions in the BTS as needed.

Regards,
Salvatore