CVE-2010-2453 in DSM
Summary
by MITRE
Multiple cross-site scripting (XSS) vulnerabilities in Synology Disk Station 2.x before DSM3.0-1337 allow remote attackers to inject arbitrary web script or HTML by connecting to the FTP server and providing a crafted (1) USER or (2) PASS command, which is written by the FTP logging module to a web-interface log window, related to a "web commands injection" issue.
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Analysis
by VulDB Data Team • 02/07/2019
The vulnerability CVE-2010-2453 represents a critical cross-site scripting flaw in Synology Disk Station 2.x firmware versions prior to DSM3.0-1337. This vulnerability stems from improper input validation within the FTP server component that processes user authentication commands. When remote attackers establish connections to the FTP service and submit maliciously crafted USER or PASS commands, the system fails to adequately sanitize these inputs before logging them to web-interface accessible log windows. The flaw creates a direct injection vector where attacker-controlled content can be executed within the context of authenticated users' browsers, leveraging the web interface's trust relationship with legitimate users.
The technical exploitation mechanism relies on the FTP logging module's handling of authentication data without proper sanitization or encoding. When the FTP server processes the malicious USER or PASS commands, it stores these inputs verbatim in web-accessible log files that are subsequently displayed in the web interface's log viewing functionality. This creates a classic reflected XSS scenario where the malicious payload is stored server-side and executed when legitimate users view the log entries. The vulnerability specifically targets the web commands injection issue, where the FTP server's logging functionality becomes an attack surface for web-based malicious code execution. This flaw operates under CWE-79 which defines cross-site scripting vulnerabilities as the failure to properly sanitize user-controllable input data, and aligns with ATT&CK technique T1566.001 for initial access through malicious web content.
The operational impact of this vulnerability extends beyond simple script execution as it enables attackers to perform session hijacking, credential theft, and privilege escalation within the affected system. An attacker who successfully exploits this vulnerability can execute arbitrary JavaScript code in the context of authenticated users' browsers, potentially leading to full system compromise if users have administrative privileges. The attack requires minimal privileges since it only necessitates access to the FTP service, which is typically enabled by default on Synology devices. This makes the vulnerability particularly dangerous as it can be exploited by unauthenticated attackers who simply need to connect to the FTP server and submit malicious commands. The web interface log viewing functionality becomes a critical attack vector where legitimate users inadvertently execute malicious payloads, creating a persistent threat that can affect multiple users over time.
Mitigation strategies for CVE-2010-2453 should focus on immediate firmware updates to DSM3.0-1337 or later versions where Synology addressed this vulnerability through proper input sanitization and output encoding. Network administrators should implement firewall rules to restrict FTP access to trusted networks only, as disabling the FTP service entirely would eliminate the attack surface. The implementation of web application firewalls can provide additional protection by filtering malicious payloads in transit, though this represents a secondary defense mechanism. Regular security audits should include verification of FTP service configurations and monitoring for suspicious log entries that might indicate exploitation attempts. Organizations should also consider implementing user education programs to raise awareness about the risks of accessing potentially compromised web interfaces, particularly when dealing with system logs that may contain untrusted data from network services. The vulnerability demonstrates the critical importance of input validation in network services that interact with web-based management interfaces, highlighting how seemingly benign logging functionality can become a significant security risk when proper sanitization is not implemented.