CVE-2004-1778 in Skype
Summary
by MITRE
Skype 0.92.0.12 and 1.0.0.1 for Linux, and possibly other versions, creates the /usr/share/skype/lang directory with world-writable permissions, which allows local users to modify language files and possibly conduct social engineering or other attacks.
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Analysis
by VulDB Data Team • 07/16/2017
The vulnerability described in CVE-2004-1778 represents a critical privilege escalation and data integrity issue within Skype versions 0.92.0.12 and 1.0.0.1 for Linux operating systems. This flaw stems from improper permission configuration during the application installation process where the system creates the /usr/share/skype/lang directory with world-writable permissions. The root cause of this vulnerability can be classified under CWE-732, which specifically addresses incorrect permissions for critical resources, and falls within the broader category of improper access control issues. The flaw creates an attack surface that allows any local user to modify language files within this directory, potentially compromising the integrity of the application's user interface and communication features.
The operational impact of this vulnerability extends beyond simple file modification capabilities and presents significant security implications for system integrity and user trust. Attackers with local access can leverage this weakness to inject malicious content into language files, which could then be executed or displayed to other users within the Skype application. This opens the door to various social engineering attacks where attackers might modify error messages, user interface text, or communication prompts to deceive users into revealing sensitive information or performing unintended actions. The vulnerability specifically enables path traversal and file injection attacks, allowing malicious actors to potentially manipulate how the application presents information to users, thereby undermining the application's security model and user confidence in the authenticity of displayed content.
From a cybersecurity perspective, this vulnerability aligns with several ATT&CK framework techniques including T1068, which covers 'Exploitation for Privilege Escalation,' and T1566, which addresses 'Phishing for Information.' The flaw essentially provides a backdoor mechanism for local users to modify application components without proper authorization, potentially leading to more sophisticated attacks when combined with other vulnerabilities. The world-writable permission structure creates a persistent threat vector that remains active as long as the vulnerable Skype version is installed on the system. This vulnerability also demonstrates poor security hygiene in application deployment and configuration management, as proper privilege separation and access control mechanisms should have prevented the creation of such insecure directory structures.
Mitigation strategies for this vulnerability must address both immediate remediation and long-term security architecture improvements. The most direct solution involves correcting the directory permissions immediately after installation by setting appropriate ownership and access controls using standard unix permission models. System administrators should ensure that the /usr/share/skype/lang directory is owned by the appropriate user group and has restrictive permissions that prevent unauthorized modifications. Additionally, implementing automated security scanning tools that can detect and alert on improper permission configurations helps maintain ongoing security posture. The vulnerability also highlights the importance of secure coding practices and proper privilege management during application development, emphasizing the need for applications to properly configure their installation directories with appropriate access controls from the outset. Regular security audits of installed applications should include checks for similar permission misconfigurations across the entire system to prevent similar issues from persisting in other software components.