CVE-2008-5730 in NetCat
Summary
by MITRE
Multiple CRLF injection vulnerabilities in AIST NetCat 3.12 and earlier allow remote attackers to have an unknown impact via unspecified vectors involving (1) a %0a sequence in a cookie and (2) the add.php file.
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Analysis
by VulDB Data Team • 11/20/2024
The vulnerability identified as CVE-2008-5730 represents a critical CRLF (Carriage Return Line Feed) injection flaw discovered in AIST NetCat version 3.12 and earlier. This type of vulnerability falls under the broader category of input validation weaknesses that can be exploited to manipulate HTTP headers and potentially execute malicious code. The vulnerability manifests through two distinct attack vectors involving the manipulation of HTTP cookie values and the add.php file, making it particularly dangerous as it can be exploited through multiple entry points within the application. CRLF injection vulnerabilities are classified under CWE-113 in the Common Weakness Enumeration framework, which specifically addresses improper neutralization of CRLF characters in HTTP headers.
The technical exploitation of this vulnerability occurs when an attacker injects CRLF sequences into HTTP headers through manipulated cookie values or by targeting the add.php file. When the application processes these inputs without proper sanitization, the injected CRLF characters can be interpreted as HTTP header terminators, allowing attackers to inject additional headers or manipulate existing ones. This manipulation can lead to various security consequences including HTTP response splitting, cache poisoning, cross-site scripting attacks, and session hijacking. The %0a sequence represents the hexadecimal encoding of a line feed character, which when injected into cookie values can effectively break out of the intended cookie value context and inject malicious headers.
The operational impact of CVE-2008-5730 extends beyond simple data manipulation as it can enable sophisticated attack vectors that compromise the integrity of web applications and user sessions. Attackers can leverage this vulnerability to perform HTTP response splitting attacks where they inject malicious headers that can cause the web server to send multiple responses to a single request, potentially leading to cache poisoning attacks. This vulnerability also aligns with several tactics described in the MITRE ATT&CK framework under the 'Command and Control' and 'Initial Access' phases, as it can be used to establish persistent access to systems through manipulated session handling or header injection techniques. The impact on affected systems can range from session theft to complete application compromise, depending on the specific implementation and the attacker's objectives.
Mitigation strategies for CVE-2008-5730 require immediate implementation of input validation and sanitization measures across all user-supplied data, particularly HTTP headers and cookie values. Organizations should implement strict validation of all incoming data, rejecting or encoding any CRLF characters that appear in HTTP headers or cookie values. The recommended approach involves implementing proper encoding of user input before it is processed or stored, ensuring that HTTP headers are constructed using safe methods that prevent injection attacks. Additionally, upgrading to a patched version of AIST NetCat or implementing proper header validation mechanisms within the application itself can effectively prevent exploitation. Security teams should also consider implementing web application firewalls that can detect and block CRLF injection attempts, and conduct regular security testing to identify similar vulnerabilities in other components of the web application stack. The vulnerability demonstrates the critical importance of proper input validation in web applications and serves as a reminder of the potential consequences when such fundamental security measures are not properly implemented.