CVE-2006-2131 in Advanced Poll
Summary
by MITRE
include/class_poll.php in Advanced Poll 2.0.4 uses the HTTP_X_FORWARDED_FOR (X-Forwarded-For HTTP header) to identify the IP address of a client, which makes it easier for remote attackers to spoof the source IP and bypass voting restrictions.
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Analysis
by VulDB Data Team • 09/08/2017
The vulnerability described in CVE-2006-2131 represents a critical security flaw in the Advanced Poll 2.0.4 web application that fundamentally undermines the integrity of its voting system. This issue stems from the application's improper handling of HTTP headers, specifically the HTTP_X_FORWARDED_FOR header, which is commonly used in web environments where applications operate behind load balancers or proxy servers. The application's developers chose to rely on this header for identifying client IP addresses during the voting process, creating a significant security weakness that directly violates standard web security practices.
The technical implementation flaw occurs when the application processes the X-Forwarded-For HTTP header without proper validation or sanitization of its contents. This header is designed to identify the original IP address of a client when requests pass through multiple proxies or load balancers, but it can be easily manipulated by malicious actors who control the request headers. The vulnerability falls under the category of trust boundary violations and demonstrates poor input validation practices that align with CWE-20, which addresses improper input validation in software applications. Attackers can simply inject a spoofed IP address into the X-Forwarded-For header to appear as if they are coming from a different IP address, effectively bypassing any IP-based restrictions that the application implements to prevent duplicate voting.
The operational impact of this vulnerability is severe and multifaceted, as it directly enables vote manipulation and potentially fraudulent activity within the polling system. Remote attackers can exploit this weakness to cast multiple votes from different IP addresses, undermining the entire purpose of the poll and potentially compromising the validity of results. This vulnerability particularly affects online polling systems where IP address restrictions are implemented as a security measure to prevent duplicate voting, which is a common practice in web applications. The attack vector is straightforward and requires minimal technical expertise, making it particularly dangerous as it can be exploited by anyone with basic web request manipulation capabilities. The vulnerability also demonstrates a lack of proper security controls that would normally be expected in web applications, as the system fails to implement proper authentication or session management to verify the legitimacy of voting attempts.
The security implications extend beyond simple vote manipulation to encompass broader concerns about data integrity and system trust. This vulnerability creates a pathway for attackers to circumvent access controls and potentially gain unauthorized influence over the outcome of polls or surveys. From an attacker's perspective, this represents a low-effort, high-impact method of bypassing security measures that should be fundamental to any web application's design. The issue also highlights the importance of proper header validation and the dangers of relying on HTTP headers that can be easily manipulated by clients. Organizations implementing similar systems should consider this vulnerability as a prime example of why proper input validation, header sanitization, and robust authentication mechanisms are essential for maintaining system integrity and preventing unauthorized access or manipulation of critical data. The vulnerability's classification under ATT&CK framework would likely fall under privilege escalation or defense evasion techniques where attackers exploit weak input validation to bypass access controls and manipulate system behavior.