CVE-2002-1308 in Navigator
Summary
by MITRE
Heap-based buffer overflow in Netscape and Mozilla allows remote attackers to execute arbitrary code via a jar: URL that references a malformed .jar file, which overflows a buffer during decompression.
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Analysis
by VulDB Data Team • 09/06/2025
The vulnerability described in CVE-2002-1308 represents a critical heap-based buffer overflow affecting web browsers from the Netscape and Mozilla families. This flaw specifically manifests when browsers attempt to process jar: URLs that reference malformed java archive files during the decompression process. The vulnerability operates at the intersection of web browser security and software decompression protocols, creating a pathway for remote code execution through carefully crafted malicious content. The issue stems from inadequate input validation during the handling of compressed archive files, which are commonly used for distributing java applets and web applications.
The technical implementation of this vulnerability involves a heap-based buffer overflow occurring during the decompression phase of .jar file processing. When a browser encounters a jar: URL pointing to a malformed archive, the decompression routine fails to properly validate the size of data being extracted from the archive. This allows attackers to craft malicious .jar files that contain oversized data structures or malformed compression headers, causing the decompression algorithm to write beyond the allocated buffer boundaries in the heap memory space. The overflow typically occurs in the memory management routines responsible for handling compressed data streams, where insufficient bounds checking permits data to overwrite adjacent memory regions. This type of vulnerability falls under the CWE-121 heap-based buffer overflow category and represents a classic example of how improper input validation during decompression operations can lead to arbitrary code execution.
The operational impact of CVE-2002-1308 is severe and potentially catastrophic for affected systems. Remote attackers can exploit this vulnerability by constructing malicious .jar files that, when accessed through vulnerable browsers, trigger the buffer overflow condition. Once executed, the overflow allows attackers to overwrite critical memory locations including return addresses, function pointers, or other control data structures within the browser process. This enables attackers to redirect program execution flow to malicious code injected into the heap memory, effectively achieving remote code execution with the privileges of the compromised browser process. The attack vector is particularly dangerous because it requires no local interaction from the victim beyond visiting a malicious webpage or clicking on a link that references the compromised jar file. The vulnerability affects a wide range of web browser implementations and can be exploited across different operating systems where affected browsers are deployed, making it a significant concern for enterprise security.
Mitigation strategies for CVE-2002-1308 should focus on both immediate patching and defensive measures to protect against exploitation attempts. Organizations should prioritize updating their browser installations to versions that include fixes for the buffer overflow vulnerability, which typically involve implementing proper bounds checking during decompression operations and adding input validation for archive file contents. The fix mechanisms often include modifying the decompression routines to enforce strict size limits on extracted data and implementing memory protection techniques such as stack canaries or address space layout randomization to make exploitation more difficult. Security professionals should also consider implementing network-based protections including web application firewalls that can detect and block suspicious jar: URL patterns, content filtering systems that scan archive file contents for known malicious patterns, and browser security policies that restrict the execution of jar files from untrusted sources. Additionally, user education regarding the dangers of visiting untrusted websites and clicking on suspicious links remains crucial in reducing the attack surface. This vulnerability demonstrates the importance of robust input validation in decompression libraries and aligns with ATT&CK techniques related to code injection and privilege escalation through memory corruption vulnerabilities.