CVE-2021-30177 in PHP-Nuke
Summary
by MITRE • 04/07/2021
There is a SQL Injection vulnerability in PHP-Nuke 8.3.3 in the User Registration section, leading to remote code execution. This occurs because the U.S. state is not validated to be two letters, and the OrderBy field is not validated to be one of LASTNAME, CITY, or STATE.
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Analysis
by VulDB Data Team • 04/11/2021
The vulnerability identified as CVE-2021-30177 represents a critical security flaw in PHP-Nuke version 8.3.3 that resides within the user registration functionality. This issue manifests as a SQL injection vulnerability that can potentially lead to remote code execution, making it particularly dangerous for web applications that rely on this content management system. The vulnerability stems from insufficient input validation mechanisms that fail to properly sanitize user-provided data before processing it within database queries. Security researchers have identified that the flaw specifically targets the handling of user registration parameters, particularly those related to geographic information and data sorting preferences.
The technical implementation of this vulnerability exploits two primary validation failures that collectively create an attack surface for malicious actors. First, the system does not validate that U.S. state inputs conform to the standard two-letter postal code format, allowing attackers to inject malicious SQL commands through crafted state values. Second, the OrderBy field lacks proper validation to restrict sorting parameters to only the legitimate options of LASTNAME, CITY, or STATE. This dual failure creates a pathway where an attacker can manipulate the database query structure through user registration inputs, effectively bypassing normal input sanitization controls. The vulnerability operates under CWE-89 which specifically addresses SQL injection flaws, and it aligns with ATT&CK technique T1190 for exploitation of vulnerabilities in web applications.
The operational impact of this vulnerability extends beyond simple data manipulation, as it can enable full system compromise through remote code execution capabilities. Attackers who successfully exploit this vulnerability can potentially gain unauthorized access to the underlying database, extract sensitive user information, modify registration data, and ultimately control the web application's behavior. The attack vector is particularly concerning because it leverages the legitimate user registration process, making it difficult to distinguish malicious activity from normal user behavior. This vulnerability affects organizations using PHP-Nuke 8.3.3 who may have users registering through the public interface, creating a persistent threat that could remain undetected for extended periods.
Mitigation strategies for CVE-2021-30177 must address both the immediate validation gaps and implement broader security controls to prevent similar vulnerabilities. Organizations should immediately apply the vendor-provided security patches and updates that correct the input validation mechanisms for state codes and OrderBy parameters. Implementing proper parameterized queries and input sanitization techniques will prevent the injection of malicious SQL commands. Additionally, network-based protections such as web application firewalls can provide additional layers of defense by monitoring for suspicious input patterns. Security monitoring should include detection of unusual registration activities and validation of geographic data formats. The implementation of principle of least privilege access controls for database connections and regular security audits of web application code will further reduce the risk exposure. Organizations should also consider implementing automated vulnerability scanning tools that can identify similar validation weaknesses in other components of their web applications, as this vulnerability pattern demonstrates common security misconfigurations that may exist elsewhere in the system architecture.