CVE-2024-25389Network attack vector

Predictable random values via linear congruential generator

Published Mar 27, 2024 · Updated Nov 4, 2025

Weak random generation in RT-Thread 5.0.2 and earlier allows remote attackers to predict output used in security contexts. The calc_random and calc_urandom functions update static seeds with the same linear congruential formula and expose only bits 16 through 30 as random data. Exploitation requires a security-sensitive consumer of the random or urandom device; predictable output can undermine cryptographic protections, with no reported integrity or availability impact.

CVSS severity7.5
High
EPSS probability0.82%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Weak random generation in RT-Thread 5.0.2 and earlier allows remote attackers to predict output used in security contexts. The calc_random and calc_urandom functions update static seeds with the same linear congruential formula and expose only bits 16 through 30 as random data. Exploitation requires a security-sensitive consumer of the random or urandom device; predictable output can undermine cryptographic protections, with no reported integrity or availability impact.

The record

CVE
CVE-2024-25389
Published
Mar 27, 2024
Updated
Nov 4, 2025
Vendor
RT-Thread
Product
RT-Thread
Classifications
CWE-338
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 27, 2024CVE publishedPublication date reported by the CVE source.
  2. Nov 4, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=5.0.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

RT-Thread · RT-Threadversion=0 <=5.0.2

Published CVSS scores

7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-338Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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