CVE-2019-10686 in Apollo
Summary
by MITRE
An SSRF vulnerability was found in an API from Ctrip Apollo through 1.4.0-SNAPSHOT. An attacker may use it to do an intranet port scan or raise a GET request via /system-info/health because the %23 substring is mishandled.
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Analysis
by VulDB Data Team • 08/21/2023
The vulnerability identified as CVE-2019-10686 represents a critical server-side request forgery flaw within the Ctrip Apollo configuration management platform version 1.4.0-SNAPSHOT and earlier releases. This vulnerability stems from improper handling of the %23 substring in API requests, which allows malicious actors to manipulate the application's behavior and potentially access internal network resources that should remain protected. The affected API endpoint /system-info/health specifically exposes this weakness, making it possible for attackers to leverage the flaw for unauthorized reconnaissance and exploitation activities.
The technical implementation of this vulnerability involves the mishandling of URL encoding where the %23 character sequence, which normally represents the # symbol in URL encoding, fails to be properly processed by the application's request parsing logic. This misconfiguration allows an attacker to bypass intended access controls and redirect the application's internal requests to arbitrary internal endpoints. The vulnerability specifically affects the system's ability to validate and sanitize input parameters, creating a pathway for attackers to perform intranet port scanning activities and execute GET requests against internal services that would normally be inaccessible from external networks.
From an operational impact perspective, this vulnerability creates significant security risks for organizations utilizing Ctrip Apollo for configuration management. Attackers can exploit this flaw to map internal network topology, identify running services on internal ports, and potentially gain access to sensitive internal systems that are not exposed to the public internet. The ability to perform intranet port scanning through this vulnerability enables attackers to discover additional attack vectors and target other vulnerable internal services that may not be properly secured. The GET request capability further amplifies the risk as it allows for data exfiltration and potential command execution against internal systems.
Security practitioners should consider this vulnerability in relation to CWE-918, which specifically addresses server-side request forgery vulnerabilities, and align it with ATT&CK technique T1046 for network service scanning and T1071 for application layer protocol usage. Organizations must implement immediate mitigations including strict input validation and sanitization of all API parameters, particularly those containing URL-encoded characters. The recommended approach involves implementing comprehensive request filtering mechanisms that properly handle URL encoding sequences and prevent the bypass of access controls. Additionally, organizations should consider implementing network segmentation and firewall rules to limit access to internal services, while also monitoring API access logs for suspicious activities that may indicate exploitation attempts. Regular security assessments and penetration testing should be conducted to identify similar vulnerabilities in other application components and ensure that all input validation mechanisms are properly configured to prevent similar SSRF attacks across the entire infrastructure.