Description
changedetection.io is an open source web page change detection, website watcher, restock monitor and notification service. There is a Server Side Template Injection (SSTI) in Jinja2 that allows Remote Command Execution on the server host. Attackers can run any system command without any restriction and they could use a reverse shell. The impact is critical as the attacker can completely takeover the server machine. This can be reduced if changedetection is behind a login page, but this isn't required by the application (not by default and not enforced).
EPSS Score:
86%
Comprehensive Technical Analysis of EUVD-2024-2939
1. Vulnerability Assessment and Severity Evaluation
The vulnerability EUVD-2024-2939, also known as CVE-2024-32651 and GHSA-4r7v-whpg-8rx3, pertains to a Server Side Template Injection (SSTI) in Jinja2 within the open-source web page change detection service, changedetection.io. This vulnerability allows for Remote Command Execution (RCE) on the server host, enabling attackers to execute arbitrary system commands without restriction. The severity of this vulnerability is critical, as it can lead to a complete server takeover.
Base Score: 10.0 Base Score Version: 3.1 Base Score Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
The CVSS score of 10.0 indicates the highest level of severity due to the following factors:
- Attack Vector (AV): Network (N)
- Attack Complexity (AC): Low (L)
- Privileges Required (PR): None (N)
- User Interaction (UI): None (N)
- Scope (S): Changed (C)
- Confidentiality (C): High (H)
- Integrity (I): High (H)
- Availability (A): High (H)
2. Potential Attack Vectors and Exploitation Methods
The primary attack vector is through the injection of malicious input into the Jinja2 template engine, which is used by changedetection.io for rendering web pages. Attackers can exploit this vulnerability by crafting specific payloads that are interpreted as commands by the server, leading to RCE.
Exploitation Methods:
- Direct Injection: Attackers can inject malicious code directly into input fields that are processed by Jinja2.
- Reverse Shell: Attackers can use the RCE to establish a reverse shell, gaining persistent access to the server.
- Command Execution: Attackers can execute arbitrary system commands, including those that modify system files, install malware, or exfiltrate data.
3. Affected Systems and Software Versions
The vulnerability affects all versions of changedetection.io up to and including version 0.45.20. Users running these versions are at risk and should take immediate action to mitigate the threat.
Affected Versions:
- changedetection.io ≤ 0.45.20
4. Recommended Mitigation Strategies
Immediate Mitigation:
- Upgrade: Upgrade to the latest version of changedetection.io (version 0.45.21 or later) which includes a patch for this vulnerability.
- Access Control: Implement access control mechanisms such as login pages to restrict access to the application.
- Input Validation: Ensure that all user inputs are properly validated and sanitized before being processed by the template engine.
Long-Term Mitigation:
- Regular Updates: Keep all software and dependencies up to date.
- Security Audits: Conduct regular security audits and code reviews to identify and fix potential vulnerabilities.
- Monitoring: Implement continuous monitoring and logging to detect and respond to suspicious activities.
5. Impact on European Cybersecurity Landscape
The vulnerability poses a significant risk to organizations using changedetection.io, particularly those within the European Union. Given the critical nature of the vulnerability, it could be exploited to compromise sensitive data, disrupt services, and potentially lead to data breaches. This underscores the importance of robust cybersecurity measures and the need for timely patching and updates.
6. Technical Details for Security Professionals
Detection:
- Log Analysis: Monitor server logs for unusual command executions or suspicious activities.
- Intrusion Detection Systems (IDS): Deploy IDS to detect and alert on potential SSTI attacks.
Response:
- Incident Response Plan: Develop and implement an incident response plan to quickly address any detected exploitation attempts.
- Patch Management: Ensure that a patch management process is in place to apply security updates promptly.
Prevention:
- Code Review: Conduct thorough code reviews to identify and mitigate similar vulnerabilities.
- Security Training: Provide security training to developers and administrators to raise awareness about SSTI and other injection vulnerabilities.
References:
By addressing this vulnerability promptly and implementing robust security measures, organizations can significantly reduce the risk of exploitation and protect their systems and data.