Description
An authentication bypass vulnerability exists in the WordPress Pie Register plugin ≤ 3.7.1.4 that allows unauthenticated attackers to impersonate arbitrary users by submitting a crafted POST request to the login endpoint. By setting social_site=true and manipulating the user_id_social_site parameter, an attacker can generate a valid WordPress session cookie for any user ID, including administrators. Once authenticated, the attacker may exploit plugin upload functionality to install a malicious plugin containing arbitrary PHP code, resulting in remote code execution on the underlying server.
EPSS Score:
1%
Comprehensive Technical Analysis of EUVD-2025-20764
1. Vulnerability Assessment and Severity Evaluation
The vulnerability described in EUVD-2025-20764 is an authentication bypass issue in the WordPress Pie Register plugin versions ≤ 3.7.1.4. This vulnerability allows unauthenticated attackers to impersonate any user, including administrators, by manipulating specific parameters in a POST request to the login endpoint. The severity of this vulnerability is rated at a base score of 10.0 using CVSS version 4.0, indicating a critical risk.
CVSS Vector Breakdown:
- AV:N (Network Vector): The vulnerability is exploitable over the network.
- AC:L (Low Complexity): The attack requires low skill and resources.
- AT:N (No Authentication): No authentication is required to exploit the vulnerability.
- PR:N (No Privileges Required): No privileges are needed to exploit the vulnerability.
- UI:N (No User Interaction): No user interaction is required.
- VC:H (High Confidentiality Impact): Complete confidentiality loss.
- VI:H (High Integrity Impact): Complete integrity loss.
- VA:H (High Availability Impact): Complete availability loss.
- SC:H (High Scope Change): The vulnerability can affect other components.
- SI:H (High Scope Integrity): The vulnerability can affect the integrity of other components.
- SA:H (High Scope Availability): The vulnerability can affect the availability of other components.
2. Potential Attack Vectors and Exploitation Methods
Attack Vectors:
- Authentication Bypass: By setting
social_site=trueand manipulating theuser_id_social_siteparameter in a POST request, an attacker can generate a valid WordPress session cookie for any user ID. - Remote Code Execution (RCE): Once authenticated as an administrator, the attacker can upload a malicious plugin containing arbitrary PHP code, leading to RCE on the underlying server.
Exploitation Methods:
- Crafted POST Request: The attacker sends a specially crafted POST request to the login endpoint with manipulated parameters.
- Plugin Upload: The attacker uses the plugin upload functionality to install a malicious plugin, which can execute arbitrary PHP code.
3. Affected Systems and Software Versions
Affected Software:
- WordPress Pie Register plugin versions ≤ 3.7.1.4
Affected Systems:
- Any WordPress installation using the vulnerable versions of the Pie Register plugin.
4. Recommended Mitigation Strategies
Immediate Actions:
- Update Plugin: Immediately update the Pie Register plugin to a version higher than 3.7.1.4.
- Disable Plugin: If an update is not possible, disable the Pie Register plugin until a patched version is available.
Long-Term Mitigations:
- Regular Updates: Ensure all WordPress plugins and core files are regularly updated.
- Access Controls: Implement strict access controls and monitoring for administrative actions.
- Web Application Firewall (WAF): Deploy a WAF to detect and block suspicious POST requests.
- Code Review: Conduct thorough code reviews and security audits for all plugins and custom code.
5. Impact on European Cybersecurity Landscape
The vulnerability poses a significant risk to the European cybersecurity landscape, particularly for organizations and individuals using WordPress with the Pie Register plugin. The potential for unauthenticated attackers to gain administrative access and execute arbitrary code can lead to data breaches, unauthorized access, and service disruptions. This underscores the importance of timely patch management and continuous monitoring of web applications.
6. Technical Details for Security Professionals
Exploit Details:
- Vulnerable Endpoint: The login endpoint of the Pie Register plugin.
- Parameters:
social_site=trueanduser_id_social_site - Session Cookie Generation: Manipulating the
user_id_social_siteparameter allows the generation of a valid session cookie for any user ID.
Detection and Response:
- Log Analysis: Monitor logs for unusual POST requests to the login endpoint.
- Intrusion Detection Systems (IDS): Implement IDS rules to detect and alert on suspicious login attempts.
- Incident Response: Have an incident response plan in place to quickly address any detected exploitation attempts.
References:
- Metasploit Framework Exploit
- Exploit Database Entry
- Pie Register Plugin GitHub
- WordPress Plugin Page
- VulnCheck Advisory
Aliases:
- CVE-2025-34077
Assigner:
- VulnCheck
EPSS Score:
- 1 (indicating a high likelihood of exploitation)
ENISA IDs:
- Product:
ca341b1a-4518-3742-aabc-8db855888a84 - Vendor:
c38f71ba-6cb2-3c44-9654-4b9648690300
By addressing this vulnerability promptly and implementing robust security measures, organizations can mitigate the risk of exploitation and protect their WordPress installations from potential attacks.