dbcve.org
Mbed TlsApplication · Trustedfirmware

CVE-2024-49195

CRITICAL · 9.8 CVSS v3.1 Published 2024-10-15
Fix available
A fix is available. Upgrade to 3.6.2 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Mbed TLS 3.5.x through 3.6.x before 3.6.2 has a buffer underrun in pkwrite when writing an opaque key pair

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Mbed TLS versions 3.5.x through 3.6.x contain a buffer underrun vulnerability in the pkwrite function that occurs when writing an opaque key pair. The vulnerability allows writing data before the start of a memory buffer, leading to potential memory corruption and, given the critical CVSS score, possible remote code execution.

MitigationUpgrade Mbed TLS to version 3.6.2 or later. If immediate patching is not feasible, avoid using the pkwrite function with opaque key pairs until the update can be applied.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Mbed TlsApplication
Affected:>= 3.5.0, < 3.6.2

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed Mbed TLS version
    Locate the mbedtls header file (usually mbedtls/version.h or check library binary) and read the MBEDTLS_VERSION_NUMBER or MBEDTLS_VERSION_MAJOR/MINOR/PATCH macros. Alternatively, run: grep -r 'MBEDTLS_VERSION' /path/to/mbedtls/include/mbedtls/ or use pkg-config if installed via package manager.
    Affected if The version is 3.5.0 through 3.6.1 inclusive (any version >= 3.5.0 and < 3.6.2)
  2. Locate pkwrite function usage in codebase
    Search source files for calls to mbedtls_pk_write_keypair or mbedtls_pk_write_pubkey functions. Use: grep -rn 'mbedtls_pk_write' /path/to/source/code/
    Affected if Code calls pkwrite-related functions (mbedtls_pk_write_keypair, mbedtls_pk_write_pubkey, or their PK backend variants)
  3. Determine if opaque key pairs are used with pkwrite
    Examine the pkwrite calls found in step 2. Check the key context being passed - opaque keys are typically created with mbedtls_pk_setup_parses: opaque keys are RSA or EC keys loaded via mbedtls_pk_parse_key() with the MBEDTLS_PK_RSA or MBEDTLS_PK_ECKEY parsing context, or keys generated with mbedtls_pk_setup() using an RSA/EC context. Review the mbedtls_pk_context structure initialization.
    Affected if The pkwrite function is being called with an opaque RSA or EC key pair (mbedtls_pk_context initialized with RSA or EC key type, not a parsed public/private key file directly)
  4. Check for compiled-in PK module
    Verify mbed TLS was compiled with the PK module enabled. Look for MBEDTLS_PK_C defined in mbedtls/config.h or check if libmbedcrypto.a/so includes pk.o. Use: grep 'MBEDTLS_PK_C' /path/to/mbedtls/include/mbedtls/config.h
    Affected if MBEDTLS_PK_C is defined (module is compiled in)

You are affected if Mbed TLS version is 3.5.0-3.6.1 AND your code uses mbedtls_pk_write_keypair or mbedtls_pk_write_pubkey with an opaque RSA or EC key pair.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 3.6.2 or later
Fixed in 3.6.2
Interim mitigation

Upgrade Mbed TLS to version 3.6.2 or later. If immediate patching is not feasible, avoid using the pkwrite function with opaque key pairs until the update can be applied.

Recommended fix High confidence

Mbed TLS 3.6.2

  1. Identify the current Mbed TLS version in use by checking project dependencies or library version
  2. Upgrade Mbed TLS library to version 3.6.2 or later
  3. Rebuild and recompile the application with the updated Mbed TLS library
  4. Verify the pkwrite functionality works correctly with the new library version
  5. Test the application to ensure no regressions were introduced

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Mbed Tls Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing8.0 h
  • Review / QA4.0 h
18.0 hours of engineering $3,040
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,864.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2024-49195 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data