CVE-2017-11148 in Chat
Summary
by MITRE
Server-side request forgery (SSRF) vulnerability in link preview in Synology Chat before 1.1.0-0806 allows remote authenticated users to access intranet resources via unspecified vectors.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 12/15/2022
The vulnerability identified as CVE-2017-11148 represents a server-side request forgery flaw within the link preview functionality of Synology Chat versions prior to 1.1.0-0806. This security weakness specifically affects the application's handling of external link previews, creating a pathway for malicious actors to exploit the system's network communication capabilities. The vulnerability exists in the server-side processing of URL requests when users share links within the chat environment, allowing unauthorized access to internal network resources through crafted malicious inputs.
The technical implementation of this SSRF vulnerability stems from inadequate input validation and sanitization within the link preview mechanism. When users share links in Synology Chat, the system attempts to fetch metadata and preview information from the specified URL. However, the application fails to properly restrict or validate the destinations of these requests, enabling attackers to manipulate the underlying HTTP requests to target internal systems. This flaw operates at the application layer and demonstrates a classic SSRF pattern where the server acts as an intermediary to make requests on behalf of the attacker, bypassing normal network security controls.
The operational impact of this vulnerability extends beyond simple information disclosure, as it allows authenticated users to potentially access sensitive internal network resources that should remain protected from external access. Attackers could leverage this weakness to enumerate internal services, access restricted APIs, or even attempt to exploit other vulnerabilities within the internal network infrastructure. The authentication requirement does not sufficiently protect against this attack vector, as the vulnerability exists in the privilege escalation and access control mechanisms within the application's network handling capabilities. This represents a significant risk to organizations relying on Synology Chat for internal communications, as it could enable lateral movement and reconnaissance activities by threat actors.
Organizations should implement immediate mitigations including upgrading to Synology Chat version 1.1.0-0806 or later, which contains the necessary patches to address this vulnerability. Network-level controls such as implementing proper firewall rules to restrict outbound connections from the chat server, and employing web application firewalls to monitor and filter suspicious requests, provide additional defense layers. The vulnerability aligns with CWE-918, which specifically addresses server-side request forgery, and maps to ATT&CK technique T1071.004 for application layer protocol, where adversaries exploit web application vulnerabilities to access internal resources. Additionally, implementing proper input validation and sanitization practices, including URL scheme restrictions and hostname whitelisting, would significantly reduce the attack surface for similar vulnerabilities in the future.