Rt ThreadApplication

CVE-2024-25389

HIGH · 7.5 CVSS v3.1 Published 2024-03-27
Fix available
A fix is available. Upgrade to after 5.0.2 or later.
See remediation →
84/100
Remediation priority · High
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
RT-Thread through 5.0.2 generates random numbers with a weak algorithm of "seed = 214013L * seed + 2531011L; return (seed >> 16) & 0x7FFF;" in calc_random in drivers/misc/rt_random.c.

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

RT-Thread through 5.0.2 uses a weak Linear Congruential Generator (LCG) for random number generation in calc_random (drivers/misc/rt_random.c). The algorithm uses predictable math (seed = 214013L * seed + 2531011L) and only returns 15 bits, making generated numbers easily predictable by attackers who can observe outputs.

MitigationReplace the weak RNG in calc_random with a cryptographically secure pseudo-random number generator (CSPRNG) such as a hardware RNG, ChaCha20, or Mersenne Twister, and audit all code paths using this function for security-sensitive operations.

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
Rt ThreadApplication
Affected:<= 5.0.2

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
None
Availability
None

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

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 RT-Thread installation
    Check your project or system for the presence of RT-Thread by looking for its directory structure, header files (typically under include/rtthread.h), or build artifacts that reference RT-Thread components
    Affected if RT-Thread is present in your environment
  2. Determine RT-Thread version
    Locate the version file or header (often found as version.h or in the root directory of RT-Thread) and check the defined version number or tag
    Affected if The version is 5.0.2 or lower, or if you cannot determine a version and are using RT-Thread
  3. Verify vulnerable file exists
    Search for the file drivers/misc/rt_random.c in your RT-Thread source tree and confirm its presence
    Affected if The file drivers/misc/rt_random.c exists in your codebase
  4. Inspect calc_random implementation
    Open drivers/misc/rt_random.c and locate the calc_random function; verify it uses the LCG formula (seed = 214013L * seed + 2531011L) and returns a 15-bit value
    Affected if The calc_random function contains the weak LCG algorithm with 15-bit output as described
  5. Identify usage of calc_random
    Search your codebase for calls to calc_random or rt_random function, particularly in security-sensitive contexts such as key generation, session tokens, cryptographic operations, or authentication mechanisms
    Affected if calc_random is called from code that handles passwords, tokens, keys, or other security-critical operations

You are affected if you use RT-Thread version 5.0.2 or lower and your application relies on calc_random for any security-sensitive random number generation.

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.

From vendor data
Upgrade available Upgrade to a release after 5.0.2
Interim mitigation

Replace the weak RNG in calc_random with a cryptographically secure pseudo-random number generator (CSPRNG) such as a hardware RNG, ChaCha20, or Mersenne Twister, and audit all code paths using this function for security-sensitive operations.

Fix this in Rt Thread Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,176.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2024-25389 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

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-2024-25389 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