CVE-2006-2312 in Skype
Summary
by MITRE
Argument injection vulnerability in the URI handler in Skype 2.0.*.104 and 2.5.*.0 through 2.5.*.78 for Windows allows remote authorized attackers to download arbitrary files via a URL that contains certain command-line switches.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 06/22/2025
The vulnerability identified as CVE-2006-2312 represents a critical argument injection flaw within Skype's URI handler implementation on Windows platforms. This security weakness affects Skype versions 2.0..104 and 2.5..0 through 2.5.*.78, where the application fails to properly sanitize command-line arguments passed through URI schemes. The vulnerability stems from insufficient input validation mechanisms that allow malicious actors to inject arbitrary command-line switches into the Skype application's execution context. When a user clicks on a specially crafted URL containing these malicious arguments, the Skype client processes them without adequate sanitization, creating an attack surface that can be exploited by remote authorized attackers. The flaw specifically resides in how Skype handles URI protocol handlers, particularly when processing URLs that contain command-line parameters that should be treated as data rather than executable instructions.
This vulnerability operates at the intersection of several security domains including input validation, command injection, and privilege escalation. The technical implementation flaw allows for arbitrary file download capabilities through the manipulation of URI parameters that are intended to be processed as application arguments. When a user interacts with a maliciously crafted URL, the Skype client's URI handler parses these parameters without proper isolation or sanitization, enabling attackers to inject commands that can trigger file downloads or other unauthorized operations. The attack vector is particularly concerning because it leverages social engineering through URL delivery, making it accessible to attackers who can convince users to click on malicious links. The vulnerability demonstrates poor adherence to secure coding practices and lacks proper parameter validation mechanisms that would normally prevent such injection attacks. From a cybersecurity perspective, this represents a classic example of how protocol handler implementations can become attack vectors when proper input sanitization is omitted.
The operational impact of this vulnerability extends beyond simple file downloads to potentially enable more sophisticated attacks within the targeted system. Attackers who successfully exploit this vulnerability can leverage the Skype client's execution context to download and potentially execute arbitrary files, creating opportunities for malware deployment or privilege escalation. The affected Skype versions represent a significant portion of the user base at the time of discovery, making this vulnerability particularly dangerous for widespread exploitation. The fact that this affects both Skype 2.0 and 2.5 series versions indicates a persistent flaw in the URI handling implementation that was not adequately addressed across multiple release streams. Organizations using these versions of Skype face substantial risk of unauthorized file transfers and potential system compromise, especially in enterprise environments where users may inadvertently click on malicious links. The vulnerability also highlights the importance of proper URI handler security in instant messaging applications, as these systems often have elevated privileges and access to network resources.
Mitigation strategies for CVE-2006-2312 should focus on immediate patching and configuration hardening measures. Microsoft recommends updating to newer Skype versions that address the URI handling vulnerability, as the original affected versions lack proper input validation. Organizations should implement URL filtering mechanisms that can detect and block suspicious URI patterns, particularly those containing command-line switches or unusual parameter combinations. Network administrators should consider disabling or restricting Skype's URI handler registration in the Windows registry if the application is not essential for business operations. The implementation of application whitelisting solutions can help prevent execution of unauthorized file downloads triggered by malicious URLs. Additionally, user education programs should emphasize the importance of verifying URL sources before clicking on links, particularly in email communications or web browsing contexts. From a compliance perspective, this vulnerability aligns with several security frameworks including the CWE catalog under category 78 for command injection vulnerabilities and maps to ATT&CK techniques related to social engineering and execution through web-based attacks. The vulnerability underscores the critical need for secure URI handler implementations and proper input validation in client-side applications that process external data sources.