CVE-2013-1648 in Server
Summary
by MITRE
The Subscriptions feature in Open-Xchange Server before 6.20.7 rev14, 6.22.0 before rev13, and 6.22.1 before rev14 does not properly validate the publication-source URL, which allows remote authenticated users to trigger arbitrary outbound TCP traffic via a crafted Source field, as demonstrated by (1) an ftp: URL, (2) a gopher: URL, or (3) an http://127.0.0.1/ URL, related to a "Server-side request forging (SSRF)" issue.
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Analysis
by VulDB Data Team • 10/25/2024
The vulnerability identified as CVE-2013-1648 represents a critical server-side request forgery flaw within the Open-Xchange Server platform that affects multiple version ranges including 6.20.7 rev14, 6.22.0 rev13, and 6.22.1 rev14. This issue resides within the Subscriptions feature where the system fails to properly validate publication-source URLs, creating a pathway for authenticated attackers to manipulate the server's outbound network communications. The flaw stems from inadequate input validation mechanisms that allow maliciously crafted URLs to bypass security checks and execute unauthorized network requests from the server's perspective. The vulnerability specifically targets the Source field processing within the subscription functionality, enabling attackers to construct malicious URLs that can initiate connections to arbitrary destinations, effectively turning the vulnerable server into a potential proxy for unauthorized network activity.
The technical implementation of this vulnerability demonstrates a classic server-side request forgery attack pattern that can be exploited through three primary URL schemes including ftp:, gopher:, and http://127.0.0.1/ protocols. The attack vector requires an authenticated user with sufficient privileges to access the subscription features, making it particularly dangerous in environments where user access controls may be insufficient or where users have elevated permissions. When a malicious URL is submitted through the vulnerable Source field, the server processes the request without proper validation, leading to outbound TCP connections that can reach internal network resources or external systems that the server has access to. This creates a significant risk of internal network reconnaissance and potential data exfiltration, as the server can be coerced into making connections to internal IP addresses that would normally be protected by network segmentation. The vulnerability operates at the application layer and can be classified under CWE-918 as "Server-Side Request Forgery" within the Common Weakness Enumeration framework.
The operational impact of this vulnerability extends beyond simple network connectivity issues and represents a substantial security risk for organizations using Open-Xchange Server. Attackers can leverage this flaw to perform internal network scanning by directing the server to connect to various internal IP addresses and ports, potentially discovering sensitive systems or services that should remain hidden from external access. The ability to forge requests to localhost addresses like 127.0.0.1 enables attackers to probe internal services that may not be properly secured or firewalled, potentially exposing database servers, application servers, or other critical infrastructure components. Additionally, the vulnerability can be used to perform data exfiltration by routing information through the server to attacker-controlled external systems, or to establish command and control channels that appear to originate from legitimate server infrastructure. The attack can be particularly effective in environments where the server has elevated network privileges or access to internal resources that would otherwise be restricted.
Organizations affected by this vulnerability should implement immediate mitigations including upgrading to patched versions of Open-Xchange Server where available, as the vulnerability was addressed in the specified revision numbers. Network-level mitigations should include implementing outbound firewall restrictions that prevent the server from connecting to internal IP ranges or specific ports that are not required for legitimate server operations. The implementation of proper URL validation mechanisms within the subscription features is essential, requiring strict input sanitization that rejects non-compliant URL schemes and ensures proper domain validation. Security teams should also consider implementing network monitoring solutions that can detect anomalous outbound traffic patterns that may indicate exploitation attempts, particularly connections to localhost addresses or internal network segments. Organizations should conduct thorough access control reviews to ensure that only authorized users have access to subscription features, and implement principle of least privilege configurations to minimize the potential impact of compromised accounts. This vulnerability aligns with ATT&CK technique T1071.004 for Application Layer Protocol: DNS and T1046 for Network Service Scanning, making it a significant concern for organizations implementing comprehensive threat detection and response strategies.