CVE-2002-0845 in Web Server
Summary
by MITRE
Buffer overflow in Sun ONE / iPlanet Web Server 4.1 and 6.0 allows remote attackers to execute arbitrary code via an HTTP request using chunked transfer encoding.
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Analysis
by VulDB Data Team • 09/13/2025
The vulnerability identified as CVE-2002-0845 represents a critical buffer overflow flaw in Sun ONE and iPlanet Web Server versions 4.1 and 6.0 that exposes systems to remote code execution attacks. This vulnerability specifically manifests when the web server processes HTTP requests employing chunked transfer encoding, a standard method for transmitting data in HTTP/1.1 protocols. The flaw arises from inadequate input validation and memory management within the server's handling of chunked data streams, creating exploitable conditions that allow attackers to overflow buffer boundaries and potentially gain unauthorized system access.
The technical implementation of this vulnerability stems from the web server's failure to properly validate the length specifications of chunked data segments during HTTP request processing. When an attacker crafts a malicious HTTP request with malformed chunked encoding parameters, the server's internal buffer allocation mechanisms become overwhelmed, causing memory corruption that can be leveraged to overwrite critical program execution pointers. This type of buffer overflow directly aligns with CWE-121, which categorizes heap-based buffer overflows as a fundamental weakness in memory management. The vulnerability operates at the application layer and can be exploited through network-based attacks without requiring any local system access or authentication credentials.
The operational impact of CVE-2002-0845 extends beyond simple service disruption to encompass complete system compromise and potential data breaches. Successful exploitation allows remote attackers to execute arbitrary code with the privileges of the web server process, typically running with elevated system permissions. This presents attackers with opportunities to establish persistent backdoors, escalate privileges to system administrators, or use the compromised server as a launch point for lateral movement within network infrastructures. The vulnerability's remote exploitability means that attackers can target vulnerable systems from anywhere on the internet, making it particularly dangerous for publicly accessible web servers. According to ATT&CK framework, this vulnerability maps to T1059 for command and scripting interpreter and T1078 for valid accounts, as exploitation can lead to privilege escalation and persistence mechanisms.
Mitigation strategies for CVE-2002-0845 require immediate implementation of vendor-provided patches and updates to address the specific buffer overflow conditions. Organizations should implement network segmentation and access controls to limit exposure of vulnerable web servers to untrusted networks. The deployment of web application firewalls and intrusion detection systems can help detect and block malicious chunked encoding requests before they reach the vulnerable server. Additionally, implementing proper input validation and sanitization measures, along with regular security assessments, can help identify and remediate similar vulnerabilities. System administrators should also consider disabling chunked transfer encoding functionality if it is not essential for business operations, as this provides an additional layer of defense against exploitation attempts. The vulnerability demonstrates the importance of maintaining up-to-date security patches and following secure coding practices to prevent memory corruption issues that could lead to complete system compromise.