CVE-2025-55069VulnerabilityPublished 23 Sep 2025

CVE-2025-55069: AutomationDirect CLICK PLUS C0-0x CPU firmware · Predictable Seed in Pseudo-Random Number Generator

Affects AutomationDirect CLICK PLUS C0-0x CPU firmwareSource CVE Database V5

Not known to be exploited · CVSS 8.7 High.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 4.0 base score

8.7High

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

EPSS: 0.3% chance of exploitation in 30 days – higher than 23% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: Passive
Vulnerable system confidentiality: High
Vulnerable system integrity: High
Vulnerable system availability: Low
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

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

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, 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: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: Passive: Successful exploitation of this vulnerability requires limited interaction by the targeted user with the vulnerable system and the attacker’s payload. These interactions would be considered involuntary and do not require that the user actively subvert protections built into the vulnerable system.
Vulnerable system confidentiality: High: There is a total loss of confidentiality, resulting in all information within the Vulnerable System being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.
Vulnerable system integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the vulnerable system. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the vulnerable system.
Vulnerable system availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the Vulnerable System are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 23 Sep 2025
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 2026-10-25.

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 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
AutomationDirect CLICK PLUS C0-0x CPU firmware	Affected =0	Fixed in–

AI-suggested

1. Immediate Network Segmentation: Isolate affected PLCs from general IT networks and restrict access to trusted management networks only. 2. Implement Strict Access Controls: Use firewalls and access control lists (ACLs) to limit communication to and from the PLCs, allowing only authorized devices and personnel. 3. Monitor Network Traffic: Deploy anomaly detection systems to identify unusual communication patterns or attempts to exploit the vulnerability. 4. Disable Unnecessary Services: Turn off any non-essential services or interfaces on the PLC to reduce attack surface. 5. Vendor Engagement: Maintain close contact with AutomationDirect for timely patch releases or firmware updates addressing this vulnerability. 6. Incident Response Preparedness: Develop and test response plans specific to PLC compromise scenarios, including backup and recovery procedures. 7. User Awareness: Train operational staff to recognize and report suspicious activities that might indicate exploitation attempts. 8. Cryptographic Best Practices: Where possible, implement additional layers of cryptographic protection external to the PLC to mitigate risks from compromised keys. 9. Firmware Integrity Verification: Regularly verify firmware integrity using out-of-band methods to detect unauthorized modifications. These steps go beyond generic advice by focusing on operational technology-specific controls and proactive monitoring tailored to the industrial environment.

Description

A predictable seed in pseudo-random number generator vulnerability has been discovered in firmware version 3.60 of the Click Plus PLC. The vulnerability relies on the fact that the software implements a predictable seed for its pseudo-random number generator, which compromises the security of the generated private keys.

Impact

For European organizations, especially those operating in critical infrastructure sectors such as manufacturing, energy, water treatment, and transportation, this vulnerability could have severe consequences. Exploitation could allow attackers to predict cryptographic keys, leading to unauthorized access to PLCs, manipulation of industrial processes, or interception of sensitive operational data. This could result in operational disruptions, safety hazards, financial losses, and damage to reputation. Since PLCs like the CLICK PLUS series are often integrated into larger industrial control systems, a compromise could cascade, affecting multiple systems and causing widespread downtime. Additionally, the lack of available patches means organizations must rely on compensating controls, increasing operational complexity. The vulnerability's network accessibility and lack of required privileges make it a viable target for remote attackers, including nation-state actors or cybercriminals targeting European industrial sectors. The high confidentiality and integrity impact could also lead to regulatory compliance issues under frameworks like NIS2 and GDPR if sensitive data or critical services are affected.

CWE-337Predictable Seed in Pseudo-Random Number Generator (PRNG) (opens in a new tab)
Variant weaknessOWASP Top 10 A04:2025: Cryptographic Failures (opens in a new tab)
A Pseudo-Random Number Generator (PRNG) is initialized from a predictable seed, such as the process ID or system time.
Use non-predictable inputs for seed generation.
Architecture and Design · Requirements · Libraries or Frameworks
Use products or modules that conform to FIPS 140-2 to avoid obvious entropy problems, or use the more recent FIPS 140-3 if possible.
Implementation
Use a PRNG that periodically re-seeds itself using input from high-quality sources, such as hardware devices with high entropy. However, do not re-seed too frequently, or else the entropy source might block.
OWASP Cheat Sheets
Forgot Password (opens in a new tab)
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)
OWASP ASVS 4.0.3
V2.3.1 (opens in a new tab)
V2.6.2 (opens in a new tab)
V2.7.6 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 1 Oct 2025, 00:47 UTC

WeaknessesCWE-337

Technical details

References

Community reviews

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