CVE-2006-2478 in Bitrix Site Manager
Summary
by MITRE
Bitrix Site Manager 4.1.x allows remote attackers to redirect users to other websites via a modified back_url during a HTTP POST request. NOTE: this issue has been referred to as "cross-site scripting," but that is inconsistent with the common use of the term.
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Analysis
by VulDB Data Team • 09/07/2017
The vulnerability identified as CVE-2006-2478 affects Bitrix Site Manager version 4.1.x and represents a critical security flaw that enables remote attackers to manipulate user navigation through crafted HTTP POST requests. This vulnerability specifically targets the application's handling of the back_url parameter during form submissions, allowing malicious actors to redirect users to arbitrary web destinations without their knowledge or consent. The issue demonstrates a significant weakness in the application's input validation and output sanitization mechanisms, creating an avenue for unauthorized redirection that could be exploited for phishing attacks or malicious payload delivery.
The technical implementation of this vulnerability stems from improper validation of user-supplied input within the back_url parameter. When the application processes HTTP POST requests containing this parameter, it fails to adequately sanitize or validate the input before using it to construct redirection URLs. This creates a condition where an attacker can inject malicious URLs that will be executed as part of the redirect mechanism. The flaw operates at the application layer where user input flows directly into HTTP response headers or JavaScript execution contexts without proper encoding or validation, making it susceptible to manipulation. The vulnerability is particularly concerning because it operates transparently to end users who may be unaware they are being redirected to malicious sites.
The operational impact of this vulnerability extends beyond simple redirection, as it can be leveraged in sophisticated attack scenarios that compromise user trust and potentially deliver malicious payloads. Attackers can exploit this weakness to redirect users to phishing sites that mimic legitimate banking or e-commerce portals, or to deliver malware through drive-by downloads. The vulnerability's classification as a redirector rather than traditional cross-site scripting highlights its unique characteristics within the exploit landscape, though it shares some conceptual similarities with XSS vulnerabilities in terms of user manipulation. This weakness creates a persistent threat vector that can be exploited across multiple sessions and user interactions, making it particularly dangerous for web applications that rely heavily on user navigation flows.
Security mitigations for this vulnerability require immediate implementation of input validation and output encoding measures within the Bitrix Site Manager application. The most effective approach involves implementing strict validation of the back_url parameter to ensure it conforms to expected URL formats and domain restrictions, while also implementing proper URL encoding and sanitization techniques. Organizations should consider implementing a whitelist approach for valid redirect URLs, allowing only predetermined domains or paths to be used in the back_url parameter. Additionally, the application should validate that any redirect URLs are properly encoded and that the application's redirect functionality does not accept arbitrary user input without verification. This vulnerability aligns with CWE-601 and ATT&CK techniques related to web application exploitation and user manipulation, emphasizing the need for comprehensive input validation and secure coding practices throughout the application lifecycle.