VulnerabilityPublished 4 Aug 2025

CVE-2025-41659: CODESYS Control RTE (SL) · Incorrect Permissions

Affects CODESYS Control RTE (SL)Source CVE Database V5

Not known to be exploited · CVSS 8.3 High.

Data as of 26 Oct 2026, 11:42 UTC

CVSS 3.1 base score

8.3High

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 15% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

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

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: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
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: 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 impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
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 impacted component 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 impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 4 Aug 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 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
CODESYS Control RTE (SL)	Affected =0.0.0.0	Fixed in–

AI-suggested

Immediate mitigation should focus on restricting access permissions to the PKI folder within the CODESYS Control RTE environment, ensuring that only highly privileged system processes and administrators can read or write certificate files. Network segmentation should be enforced to isolate control systems from less trusted networks, limiting remote access vectors. Implement strict access control lists (ACLs) and monitor file integrity of PKI assets to detect unauthorized changes promptly. Deploy network intrusion detection systems (NIDS) with signatures or heuristics tailored to detect anomalous access patterns to the PKI folder or certificate manipulation attempts. Additionally, enforce multi-factor authentication for administrative access and conduct regular audits of certificate trust stores to identify and revoke any unauthorized certificates. Finally, ensure that backup copies of certificates and keys are securely stored offline to enable rapid recovery if tampering occurs.

Description

A low-privileged attacker can remotely access the PKI folder of the CODESYS Control runtime system and thus read and write certificates and its keys. This allows sensitive data to be extracted or to accept certificates as trusted. Although all services remain available, only unencrypted communication is possible if the certificates are deleted.

Impact

For European organizations, especially those in industrial automation, manufacturing, and critical infrastructure sectors, this vulnerability poses a serious risk. CODESYS Control RTE is widely used in programmable logic controllers (PLCs) and embedded control systems that manage industrial processes. Unauthorized access to PKI materials can lead to interception or manipulation of encrypted communications, undermining the integrity and confidentiality of operational data. Attackers could impersonate legitimate devices or controllers by injecting trusted certificates, facilitating man-in-the-middle attacks or unauthorized command execution. Although availability is not directly impacted, the fallback to unencrypted communication increases exposure to eavesdropping and data tampering. This could result in operational disruptions, intellectual property theft, or safety hazards. The vulnerability's remote exploitability and low privilege requirement increase the attack surface, making it a critical concern for European industrial operators who rely on secure automation systems to comply with regulatory standards such as NIS2 and GDPR.

CWE-732Incorrect Permission Assignment for Critical Resource (opens in a new tab)
Class weaknessLikelihood of exploit: HighOWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product specifies permissions for a security-critical resource in a way that allows that resource to be read or modified by unintended actors.
Implementation
When using a critical resource such as a configuration file, check to see if the resource has insecure permissions (such as being modifiable by any regular user), and generate an error or even exit the software if there is a possibility that the resource could have been modified by an unauthorized party.
Architecture and Design
Divide the software into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully defining distinct user groups, privileges, and/or roles. Map these against data, functionality, and the related resources. Then set the permissions accordingly.
Architecture and Design · Operation · Sandbox or Jail
Run the code in a "jail" or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which files can be accessed in a particular directory or which commands can be executed by the software.
OWASP Cheat Sheets
REST Assessment (opens in a new tab)
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V4.3.3 (opens in a new tab)
V8.3.8 (opens in a new tab)
V13.4.2 (opens in a new tab)
Attack patterns
Accessing Functionality Not Properly Constrained by ACLs (opens in a new tab)
Directory Indexing (opens in a new tab)
Using Malicious Files (opens in a new tab)
Exploiting Incorrectly Configured Access Control Security Levels (opens in a new tab)
Signing Malicious Code (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

certvde.com/de/advisories/VDE-2025-051 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 4 Aug 2025, 08:33 UTC

WeaknessesCWE-732

Technical details

References

Community reviews

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