CVE-2002-1766 in Communicator
Summary
by MITRE
Buffer overflow in Composer in Netscape 4.77 allows local users to overwrite process memory and execute arbitrary code via a font tag with a long face attribute.
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Analysis
by VulDB Data Team • 12/21/2024
The vulnerability described in CVE-2002-1766 represents a classic buffer overflow condition that existed within the Netscape 4.77 web browser's Composer component. This flaw specifically manifests when processing HTML content containing a font tag with an excessively long face attribute value. The Composer module, which serves as Netscape's HTML editing interface, fails to properly validate the length of the face attribute before copying it into a fixed-size buffer, creating an exploitable condition that can be leveraged by local attackers to overwrite adjacent memory regions.
This buffer overflow vulnerability operates under the Common Weakness Enumeration classification of CWE-121, which encompasses stack-based buffer overflow conditions. The technical implementation involves the Composer component's insufficient input validation mechanisms when parsing HTML markup, particularly focusing on the font tag's face attribute. When a local user crafts a malicious HTML document containing a font tag with an extremely long face attribute value, the parsing routine attempts to store this data in a predetermined memory buffer that cannot accommodate the excessive input size. This overflow results in the corruption of adjacent memory locations, potentially including return addresses, function pointers, or other critical program state information that governs execution flow.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, as it provides local attackers with the capability to execute arbitrary code with the privileges of the affected process. Since the vulnerability exists within a local context, attackers must first gain access to the target system, but once achieved, they can leverage this flaw to escalate their privileges or compromise the entire system. The attack vector requires local access and involves crafting specific HTML content that triggers the memory corruption during parsing operations. This makes the vulnerability particularly dangerous in environments where users might be tricked into opening malicious documents or where automated systems process untrusted HTML content.
The security implications of CVE-2002-1766 align with the MITRE ATT&CK framework's techniques for privilege escalation and code execution. The vulnerability demonstrates the classic pattern of local privilege escalation through memory corruption attacks, where attackers can manipulate program execution flow by overwriting critical memory locations. The specific nature of this flaw places it within the domain of defensive techniques that should focus on input validation, stack protection mechanisms, and proper buffer management practices. Organizations should implement comprehensive patch management strategies to address this vulnerability, as Netscape 4.77 reached end-of-life status long before modern security practices were established. The remediation approach involves ensuring that all input parameters are properly validated against predetermined size limits and that buffer operations are performed with appropriate bounds checking mechanisms. Additionally, implementing stack canaries, address space layout randomization, and other modern exploit mitigation techniques would significantly reduce the effectiveness of similar buffer overflow attacks on contemporary systems.