CVE-2007-3577 in PHPIDS
Summary
by MITRE
PHPIDS before 20070703 does not properly handle use of the substr method in (1) document.location.search and (2) document.referrer; (3) certain use of document.location.hash; (4) certain "window[eval" and similar expressions; (5) certain Function expressions; (6) certain = expressions, as demonstrated by a whatever="something" sequence; and (7) certain "with" expressions, which allows remote attackers to inject arbitrary web script.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 10/25/2017
This vulnerability exists in PHPIDS (PHP Intrusion Detection System) versions prior to 20070703 and represents a critical input validation flaw that enables cross-site scripting injection attacks. The vulnerability stems from inadequate sanitization of JavaScript expressions within web requests, specifically targeting the substr method when used in various browser context elements. The flaw allows attackers to bypass the intrusion detection system by crafting malicious payloads that exploit how PHPIDS processes and analyzes these specific JavaScript constructs.
The technical implementation of this vulnerability involves several distinct attack vectors that all relate to improper handling of JavaScript expressions in web requests. The vulnerability specifically affects how PHPIDS processes document.location.search parameters, document.referrer values, document.location.hash components, window[eval expressions, Function constructor calls, assignment expressions with equals signs, and with statements. These elements are commonly found in web applications and are frequently used in malicious scripts to execute arbitrary code. The root cause lies in the insufficient filtering mechanisms that fail to properly identify and neutralize potentially dangerous JavaScript patterns within these contexts.
The operational impact of this vulnerability is severe as it completely undermines the security protections provided by PHPIDS, allowing remote attackers to inject malicious scripts that can execute in the context of victim browsers. Attackers can leverage this weakness to perform session hijacking, deface web applications, steal sensitive user data, or redirect users to malicious sites. The vulnerability affects any web application that relies on PHPIDS for intrusion detection, potentially compromising entire web infrastructures. The attack surface is particularly broad since these JavaScript patterns are commonly found in legitimate web traffic, making detection and prevention challenging.
Mitigation strategies should focus on upgrading to PHPIDS version 20070703 or later, which contains the necessary fixes for proper JavaScript expression handling. Organizations should also implement additional input validation layers beyond IDS systems, employ proper content security policies, and conduct regular security assessments of their web applications. The vulnerability aligns with CWE-79 (Cross-site Scripting) and follows attack patterns described in the MITRE ATT&CK framework under web application attacks. Security teams should also consider implementing web application firewalls and additional monitoring to detect anomalous JavaScript patterns in web traffic, as the vulnerability demonstrates how insufficient input sanitization can create complete bypass opportunities in security systems.