CVE-2018-8910 in Drive
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in Attachment Preview in Synology Drive before 1.0.1-10253 allows remote authenticated users to inject arbitrary web script or HTML via malicious attachments.
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Analysis
by VulDB Data Team • 10/17/2024
The vulnerability identified as CVE-2018-8910 represents a critical cross-site scripting flaw within Synology Drive's Attachment Preview functionality. This security weakness affects versions prior to 1.0.1-10253 and specifically targets the file preview component that handles document attachments. The flaw enables authenticated attackers to execute malicious scripts within the context of other users' browsers, creating a significant risk for enterprise environments where Synology Drive is deployed. The vulnerability stems from inadequate input validation and output encoding mechanisms within the attachment preview module, which fails to properly sanitize user-supplied content before rendering it in web interfaces.
The technical exploitation of this vulnerability occurs when an authenticated user accesses a maliciously crafted attachment through the Synology Drive interface. The system processes the attachment without sufficient sanitization, allowing attackers to embed malicious javascript code or html elements within the preview window. This flaw falls under CWE-79 which specifically addresses cross-site scripting vulnerabilities, where the application fails to properly validate or encode user input before incorporating it into dynamic web content. The vulnerability is particularly dangerous because it leverages the trust relationship between users and the application, enabling attackers to execute code in the context of other users' sessions.
The operational impact of this vulnerability extends beyond simple script execution, as it can lead to complete session hijacking, data exfiltration, and privilege escalation within the Synology Drive environment. Attackers can exploit this flaw to steal user credentials, access sensitive files, or manipulate the application's functionality. The remote authentication requirement does not significantly reduce the threat level since obtaining valid credentials through social engineering, credential stuffing, or other means is often feasible in enterprise environments. This vulnerability directly maps to several ATT&CK techniques including T1059 for command and scripting interpreter and T1566 for credential harvesting, making it a valuable vector for attackers seeking persistent access to network resources.
Organizations should prioritize immediate remediation by upgrading to Synology Drive version 1.0.1-10253 or later, which includes proper input validation and output encoding mechanisms. Additional mitigations should include implementing strict content security policies, monitoring for unusual attachment access patterns, and conducting regular security assessments of file sharing systems. Network segmentation and user access controls can help limit the potential impact of successful exploitation, while security awareness training can reduce the likelihood of users inadvertently triggering the vulnerability through malicious attachment downloads. The vulnerability highlights the importance of secure coding practices and input validation in web applications, particularly in enterprise file sharing solutions where users frequently handle external attachments.