VulnerabilityPublished 27 Mar 2024Updated 4 Nov 2025

CVE-2024-25389: rt-thread · PRNG

Affects rt-threadSource CVE Database V5

Not known to be exploited · CVSS 7.5 High.

Data as of 26 Oct 2026, 15:59 UTC

CVSS 3.1 base score

7.5High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.8% chance of exploitation in 30 days – higher than 57% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 27 Mar 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
GitHubrt-thread/rt-thread`pkg:github/rt-thread/rt-thread`Other threats	Affected <=5.0.2	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Replace the weak linear congruential random number generator with a cryptographically secure pseudorandom number generator (CSPRNG), such as those based on hardware entropy sources or well-vetted algorithms like Fortuna or ChaCha20-based RNGs.
Apply vendor patches or updates as soon as they become available; if none exist, consider custom firmware updates to address the RNG implementation.
Audit all cryptographic operations and security mechanisms relying on the RNG to ensure they are not vulnerable to prediction attacks.
Implement additional entropy sources where possible, such as hardware random number generators or environmental noise, to strengthen randomness.
Monitor network traffic and device behavior for anomalies that could indicate exploitation attempts targeting predictable RNG outputs.
For critical deployments, consider isolating affected devices or limiting their network exposure until mitigations are in place.
Engage with RT-Thread maintainers or vendors to prioritize a secure RNG implementation and timely patch releases.
Educate development and security teams on the importance of secure randomness in embedded systems to prevent similar issues.

Description

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.

Impact

For European organizations, especially those deploying RT-Thread in embedded systems, IoT devices, or industrial control systems, this vulnerability can lead to severe confidentiality breaches. Predictable random numbers can compromise cryptographic keys, authentication tokens, or session identifiers, enabling attackers to decrypt sensitive communications or impersonate legitimate devices. This is particularly critical in sectors like manufacturing, energy, transportation, and healthcare, where embedded devices are integral to operations and safety. The vulnerability does not affect integrity or availability directly but can facilitate further attacks that do. Since exploitation requires no privileges or user interaction and can be performed remotely, the attack surface is broad. The impact is amplified in environments where RT-Thread devices handle sensitive data or control critical infrastructure. Organizations may face regulatory and compliance risks if data confidentiality is compromised. The absence of known exploits provides a window for proactive mitigation, but the high severity score demands urgent attention.

CWE-338Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG) (opens in a new tab)
Base weaknessLikelihood of exploit: MediumOWASP Top 10 A04:2025: Cryptographic Failures (opens in a new tab)
The product uses a Pseudo-Random Number Generator (PRNG) in a security context, but the PRNG's algorithm is not cryptographically strong.
Implementation
Use functions or hardware which use a hardware-based random number generation for all crypto. This is the recommended solution. Use CyptGenRandom on Windows, or hw_rand() on Linux.
OWASP Cheat Sheets
Transport Layer Protection (opens in a new tab)
User Privacy Protection (opens in a new tab)
Password Storage (opens in a new tab)
Cryptographic Storage (opens in a new tab)
HSTS (opens in a new tab)
OWASP ASVS 4.0.3
V6.3.3 (opens in a new tab)
V6.3.2 (opens in a new tab)
V6.3.1 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 4 Nov 2025, 18:59 UTC

WeaknessesCWE-338

Technical details

References

Community reviews

Related threats