EUVD-2025-17462

Comprehensive Technical Analysis of EUVD-2025-17462

1. Vulnerability Assessment and Severity Evaluation

The vulnerability described in EUVD-2025-17462 pertains to a Sprig template injection flaw in the listmonk application. This vulnerability allows a low-privilege user to read environment variables, which can lead to significant security breaches. The CVSS (Common Vulnerability Scoring System) base score of 9.1 indicates a critical severity level. The vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H breaks down as follows:

• Attack Vector (AV): Network (N) - The vulnerability can be exploited remotely over the network.
• Attack Complexity (AC): Low (L) - The attack requires minimal skill or resources.
• Privileges Required (PR): Low (L) - The attacker needs low-level privileges to exploit the vulnerability.
• User Interaction (UI): Required (R) - Some form of user interaction is necessary for the attack to succeed.
• Scope (S): Changed (C) - The vulnerability affects resources beyond the security scope managed by the security authority.
• Confidentiality (C): High (H) - There is a high impact on the confidentiality of the data.
• Integrity (I): High (H) - There is a high impact on the integrity of the data.
• Availability (A): High (H) - There is a high impact on the availability of the system.

2. Potential Attack Vectors and Exploitation Methods

The primary attack vector involves injecting malicious code into Sprig templates, which are then processed by the listmonk application. An attacker with low-level privileges can exploit this vulnerability to read environment variables, potentially exposing sensitive information such as API keys, database credentials, or other configuration details.

Exploitation Methods:

• Template Injection: The attacker injects malicious code into the Sprig templates, which are then executed by the application.
• Environment Variable Exposure: The injected code can be crafted to read and expose environment variables, leading to unauthorized access to sensitive information.

3. Affected Systems and Software Versions

The vulnerability affects the listmonk application versions 4.0.0 through 5.0.1. The issue has been addressed in version 5.0.2. Organizations using listmonk within this version range are at risk and should prioritize updating to the latest version.

4. Recommended Mitigation Strategies

Immediate Actions:

• Update Software: Upgrade to listmonk version 5.0.2 or later, which includes the fix for this vulnerability.
• Patch Management: Implement a robust patch management process to ensure timely updates and patches for all software components.

Long-Term Strategies:

• Input Validation: Enhance input validation mechanisms to prevent template injection attacks.
• Least Privilege Principle: Ensure that users and processes operate with the minimum necessary privileges.
• Environment Variable Management: Avoid storing sensitive information in environment variables where possible. Use secure storage solutions and encryption.
• Monitoring and Logging: Implement comprehensive monitoring and logging to detect and respond to suspicious activities promptly.

5. Impact on European Cybersecurity Landscape

The vulnerability poses a significant risk to organizations within the European Union, particularly those relying on listmonk for email marketing and newsletter management. The exposure of environment variables can lead to data breaches, unauthorized access, and potential compliance violations under regulations such as GDPR.

Regulatory Implications:

• GDPR Compliance: Organizations must ensure that personal data is protected, and any breach could result in severe penalties.
• Incident Reporting: Timely reporting of incidents to relevant authorities and affected individuals is crucial to maintain compliance and trust.

6. Technical Details for Security Professionals

Vulnerability Details:

• CWE (Common Weakness Enumeration): CWE-94 (Improper Control of Generation of Code ('Code Injection'))
• Exploit Code: The specific exploit code involves injecting malicious Sprig template code that reads environment variables.

Mitigation Code:

• Patch: The fix is included in listmonk version 5.0.2. The patch ensures that Sprig templates are properly sanitized and validated to prevent injection attacks.

References:

• GitHub Advisory: GHSA-jc7g-x28f-3v3h
• Commit Reference: d27d2c32cf3af2d0b24e29ea5a686ba149b49b3e
• NVD Reference: CVE-2025-49136

Conclusion: This vulnerability underscores the importance of timely updates, robust input validation, and secure management of environment variables. Organizations should prioritize updating to the patched version of listmonk and implement additional security measures to mitigate similar risks in the future.