CVE-2018-16409 in Gogs
Summary
by MITRE
In Gogs 0.11.53, an attacker can use migrate to send arbitrary HTTP GET requests, leading to SSRF.
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Analysis
by VulDB Data Team • 05/06/2023
The vulnerability identified as CVE-2018-16409 affects Gogs version 0.11.53 and represents a server-side request forgery flaw that allows remote attackers to make arbitrary HTTP GET requests through the migration functionality. This issue stems from insufficient input validation and sanitization within the migration process, which is commonly used to import repositories from external sources. The vulnerability exists in the way Gogs handles repository migration parameters, particularly when processing URLs from external sources, creating an attack vector that can be exploited without authentication.
The technical implementation of this vulnerability occurs within the migration feature of Gogs where users can import repositories from various sources including git repositories accessible via HTTP or HTTPS protocols. When an attacker provides a malicious URL as part of the migration process, the application fails to properly validate or sanitize the input before making HTTP requests to the specified endpoint. This lack of proper validation allows the application to make HTTP requests to internal network resources that should normally be inaccessible from the external network, effectively bypassing network segmentation controls. The flaw is classified under CWE-918 as a server-side request forgery vulnerability, where the application's trust in user-provided input leads to unauthorized requests being made on behalf of the server.
The operational impact of this vulnerability is significant as it enables attackers to perform reconnaissance and potentially exploit internal services that are not directly exposed to the internet. An attacker could leverage this vulnerability to scan internal network ranges, access internal services such as databases, web applications, or other systems that are typically protected by firewalls and network segmentation. The vulnerability can also be used to access internal APIs or services that might contain sensitive information or provide administrative capabilities. This type of attack aligns with ATT&CK technique T1016 which involves the discovery of network endpoints, and T1046 which covers the discovery of services on remote systems. The attack could potentially lead to further privilege escalation or lateral movement within a network environment.
Mitigation strategies for this vulnerability include implementing strict input validation and sanitization for all migration parameters, particularly those related to URLs and endpoints. Organizations should restrict the migration functionality to trusted sources only and implement proper network segmentation to prevent internal service access from external systems. Additionally, implementing outbound firewall rules to restrict HTTP requests from the Gogs server to internal network resources can help contain the impact. The most effective long-term solution involves upgrading to a patched version of Gogs where proper input validation has been implemented and the migration functionality has been hardened against malicious input. Security monitoring should also be enhanced to detect unusual HTTP requests originating from the Gogs server, which could indicate exploitation attempts. Organizations should also consider implementing network access controls that prevent the Gogs server from making arbitrary HTTP requests to internal resources without explicit authorization.