CVE-2007-4042 in Navigator
Summary
by MITRE
Multiple argument injection vulnerabilities in Netscape Navigator 9 allow remote attackers to execute arbitrary commands via a NULL byte (%00) and shell metacharacters in a (1) mailto, (2) nntp, (3) news, (4) snews, or (5) telnet URI, a similar issue to CVE-2007-3670.
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Analysis
by VulDB Data Team • 09/06/2018
The vulnerability described in CVE-2007-4042 represents a critical argument injection flaw affecting Netscape Navigator 9, which demonstrates the persistent security challenges associated with URI parsing and command execution in web browsers. This vulnerability specifically targets the handling of various URI schemes including mailto, nntp, news, snews, and telnet, where the browser fails to properly sanitize input parameters before passing them to underlying system commands. The exploitation mechanism leverages NULL byte injection combined with shell metacharacters to bypass security controls and execute arbitrary code on the affected system. This type of vulnerability falls under the category of command injection attacks where attacker-controlled input is directly incorporated into system commands without proper validation or encoding.
The technical implementation of this vulnerability stems from inadequate input validation within the browser's URI handler routines, particularly when processing mailto and news-related protocols. When a user clicks on a maliciously crafted URI containing a NULL byte followed by shell metacharacters, the browser's parsing logic fails to properly escape or sanitize these special characters before they are passed to the operating system's command processing layer. This flaw creates a direct pathway for attackers to inject malicious commands that can be executed with the privileges of the browser process, potentially leading to complete system compromise. The vulnerability is particularly dangerous because it operates at the protocol level rather than within web application code, making it more difficult to detect and mitigate through traditional web application security measures.
From an operational impact perspective, this vulnerability exposes users to significant risk when browsing the internet, particularly in environments where Netscape Navigator 9 is the default browser or when users encounter malicious web content through email or news feeds. The attack surface is broad given that multiple URI schemes are affected, increasing the likelihood of successful exploitation through various attack vectors. Security professionals should note that this vulnerability operates in accordance with attack patterns documented in the ATT&CK framework under the command and control category, specifically targeting the execution of arbitrary code through legitimate system interfaces. The vulnerability's similarity to CVE-2007-3670 indicates a systemic issue in how Netscape Navigator handles URI parameter parsing across different protocol handlers, suggesting that the flaw may have been present in multiple components of the browser's architecture.
The mitigation strategies for this vulnerability require immediate attention from system administrators and security teams responsible for maintaining Netscape Navigator 9 installations. The most effective approach involves applying vendor-provided patches that properly sanitize URI parameters before they are processed by the browser's command execution routines. Organizations should also implement network-level controls to filter out potentially malicious URIs, particularly those containing NULL bytes or shell metacharacters. Additionally, user education regarding the dangers of clicking on untrusted links and the importance of keeping browser software updated remains crucial in preventing exploitation. This vulnerability aligns with CWE-77 and CWE-88 categories, which specifically address command injection vulnerabilities and improper neutralization of special elements used in command lines. The remediation process should also include monitoring for exploitation attempts through network intrusion detection systems and reviewing system logs for evidence of unauthorized command execution. Given the age of this vulnerability and the end-of-life status of Netscape Navigator 9, organizations should consider migrating to modern browser implementations that have addressed these fundamental security issues through better input validation and sandboxing mechanisms.