CVE-2006-5925 in Links
Summary
by MITRE
Links web browser 1.00pre12 and Elinks 0.9.2 with smbclient installed allows remote attackers to execute arbitrary code via shell metacharacters in an smb:// URI, as demonstrated by using PUT and GET statements.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 04/27/2026
The vulnerability described in CVE-2006-5925 represents a critical command injection flaw affecting Links web browser version 1.00pre12 and Elinks 0.9.2 when configured with smbclient functionality. This vulnerability arises from inadequate input validation and sanitization of smb:// URIs, creating an avenue for remote code execution through maliciously crafted shell metacharacters within the URI structure. The flaw specifically manifests when the browser attempts to process SMB (Server Message Block) protocol URIs that contain shell command injection sequences, allowing attackers to execute arbitrary code on the target system with the privileges of the browser process.
The technical implementation of this vulnerability stems from the browser's improper handling of SMB URIs that include shell metacharacters such as semicolons, pipes, and other command delimiters. When the browser encounters an smb:// URI containing these characters, it passes the unescaped URI components directly to the underlying smbclient utility without proper sanitization. This design flaw falls under CWE-78, which specifically addresses Improper Neutralization of Special Elements used in OS Command Injection attacks, making it a direct instance of command injection vulnerability. The vulnerability is particularly dangerous because it leverages the legitimate smbclient functionality to execute malicious commands, bypassing traditional security controls that might not detect such indirect execution paths.
The operational impact of this vulnerability extends beyond simple code execution, as it provides attackers with a means to gain unauthorized access to systems running vulnerable browser versions. An attacker could exploit this vulnerability by crafting malicious SMB URIs containing commands such as PUT or GET statements with embedded shell metacharacters, potentially allowing for complete system compromise. The threat landscape for this vulnerability includes malicious websites, phishing campaigns, and social engineering attacks where users are tricked into clicking on crafted links. This type of attack pattern aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter: PowerShell, though in this case the injection occurs through the browser's URI handling rather than PowerShell directly.
Mitigation strategies for CVE-2006-5925 should focus on immediate patching of affected browser versions, as well as implementing network-level controls to prevent access to potentially malicious SMB URIs. Organizations should disable smbclient functionality in browsers when it is not required for business operations, and implement strict input validation for URI parsing. Network administrators should consider implementing web application firewalls or proxy servers that can detect and block suspicious URI patterns containing shell metacharacters. Additionally, user education regarding the dangers of clicking on untrusted links and the importance of keeping browser software updated remains crucial in defending against this type of attack. The vulnerability demonstrates the importance of proper input sanitization and the principle of least privilege in system design, as the exploitation requires only a simple URI manipulation rather than complex attack vectors.