EUVD-2025-20079
CVSS Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L
Lifecycle Timeline
4Description
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.
Analysis
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.
Technical Context
An out-of-bounds memory access occurs when code reads from or writes to memory locations outside the intended buffer boundaries. This vulnerability is classified as Out-of-bounds Read (CWE-125).
Affected Products
Affected products: Arm Mbed Tls
Remediation
Implement proper bounds checking on all array and buffer accesses. Use memory-safe languages or static analysis tools to detect OOB issues.
Priority Score
Vendor Status
Ubuntu
Priority: Medium| Release | Status | Version |
|---|---|---|
| oracular | ignored | end of life, was needs-triage |
| bionic | not-affected | code not present |
| focal | not-affected | code not present |
| jammy | not-affected | code not present |
| noble | not-affected | code not present |
| upstream | released | 3.6.4 |
| xenial | not-affected | code not present |
| plucky | ignored | end of life, was needed |
| questing | needed | - |
Debian
Bug #1108788| Release | Status | Fixed Version | Urgency |
|---|---|---|---|
| bullseye | not-affected | - | - |
| bullseye (security) | fixed | 2.16.9-0.1+deb11u3 | - |
| bookworm | not-affected | - | - |
| trixie | fixed | 3.6.5-0.1~deb13u1 | - |
| forky, sid | fixed | 3.6.5-0.1 | - |
| (unstable) | fixed | 3.6.4-1 | - |
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External POC / Exploit Code
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