CVE-2000-1187 in Navigator
Summary
by MITRE
Buffer overflow in the HTML parser for Netscape 4.75 and earlier allows remote attackers to execute arbitrary commands via a long password value in a form field.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 05/29/2018
The vulnerability described in CVE-2000-1187 represents a critical buffer overflow flaw within the HTML parsing component of Netscape Navigator version 4.75 and earlier releases. This security weakness specifically manifests when the browser processes form fields containing excessively long password values, creating a scenario where memory corruption can occur. The vulnerability operates at the application layer and demonstrates the dangers of inadequate input validation in web browser implementations. The flaw exists within the client-side parsing logic that handles HTML form elements, particularly those related to user authentication mechanisms where password fields are commonly employed. This type of vulnerability falls under the broader category of software security flaws that can be exploited to gain unauthorized control over affected systems. The buffer overflow occurs when the application fails to properly check the length of input data before copying it into fixed-size memory buffers, leading to memory corruption that can be leveraged by malicious actors.
The technical implementation of this vulnerability stems from improper bounds checking within Netscape's HTML parser component. When a web page contains a form field with an unusually long password value, the browser's parsing routine attempts to store this data in a predetermined memory buffer without sufficient validation of the input length. This oversight creates a situation where the input data exceeds the allocated buffer space, causing adjacent memory locations to be overwritten. The overflow can potentially overwrite critical program variables, return addresses, or other executable code, enabling attackers to redirect program execution flow. This type of memory corruption vulnerability is classified as a CWE-121 stack-based buffer overflow, which represents a common attack vector that has plagued software developers for decades. The specific nature of this flaw makes it particularly dangerous because it can be triggered through normal web browsing activities, requiring no specialized knowledge or tools beyond crafting a malicious HTML page. The vulnerability operates through the standard HTTP protocol and can be delivered through any web server hosting malicious content.
The operational impact of CVE-2000-1187 extends beyond simple denial of service conditions to enable full remote code execution capabilities. Attackers can craft malicious web pages that, when viewed in vulnerable Netscape browsers, will automatically trigger the buffer overflow condition and execute arbitrary commands on the target system. This capability allows for complete system compromise, including the potential to install malware, steal sensitive data, or establish persistent backdoors. The vulnerability affects users across various operating systems including windows and unix-based platforms where Netscape 4.75 or earlier versions are installed. The attack surface is broad as any web page containing a malicious form field could potentially exploit this vulnerability, making it particularly dangerous in environments where users browse untrusted websites. The exploitability of this vulnerability is high due to the ease with which malicious HTML content can be distributed through email attachments, compromised websites, or social engineering campaigns. The impact on enterprise security is significant as organizations relying on older Netscape browsers face potential data breaches and system compromises that could affect sensitive corporate information.
Mitigation strategies for CVE-2000-1187 require immediate action to address the underlying vulnerability through software updates and configuration changes. The primary recommendation involves upgrading to newer versions of Netscape Navigator that contain patched implementations of the HTML parser component. This upgrade process should be prioritized at the enterprise level, as older browser versions pose significant security risks that can be exploited by attackers. Organizations should also implement network-based security controls such as web application firewalls that can detect and block malicious HTML content containing overly long input fields. Additionally, user education programs should emphasize the importance of avoiding untrusted websites and maintaining current software versions. Security administrators can implement browser security policies that restrict the execution of potentially harmful content and disable unnecessary browser features that may contribute to exploitation. The vulnerability also highlights the importance of adhering to secure coding practices and conducting regular security assessments of software components. From an ATT&CK framework perspective, this vulnerability maps to techniques involving buffer overflow exploitation and remote code execution, demonstrating how legacy software vulnerabilities can be leveraged in modern attack scenarios. Organizations should also consider implementing network segmentation and monitoring to detect potential exploitation attempts and limit the lateral movement of attackers who successfully compromise vulnerable systems.