CVE-2017-7553 in RHMAP
Summary
by MITRE
The external_request api call in App Studio (millicore) allows server side request forgery (SSRF). An attacker could use this flaw to probe the network internal resources, and access restricted endpoints.
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Analysis
by VulDB Data Team • 11/20/2019
The vulnerability identified as CVE-2017-7553 resides within the external_request api call implementation in App Studio's millicore framework, representing a critical server-side request forgery flaw that fundamentally compromises network security boundaries. This vulnerability classifies under CWE-918 as a server-side request forgery, where the application fails to properly validate and sanitize external request parameters, allowing malicious actors to manipulate the system into making unauthorized requests to internal network resources. The flaw specifically affects the millicore component of App Studio, which serves as a foundational framework for enterprise application development and deployment.
The technical exploitation of this vulnerability occurs when an attacker crafts malicious requests to the external_request api endpoint, bypassing normal access controls and network segmentation measures. The system processes these requests without adequate validation of destination URLs or protocols, enabling attackers to target internal services, databases, or other sensitive resources that should remain isolated from external access. This flaw essentially transforms the application server into an unwitting proxy that can be directed to communicate with any internal endpoint, creating a pathway for reconnaissance, data exfiltration, and potential system compromise. The vulnerability demonstrates a classic lack of input validation and proper security context enforcement that violates fundamental secure coding practices.
The operational impact of CVE-2017-7553 extends far beyond simple network probing, as it enables attackers to conduct comprehensive internal network reconnaissance and potentially escalate privileges within the application environment. Attackers can leverage this vulnerability to map internal network topology, identify running services, and discover vulnerable internal systems that may not be exposed to external networks. This capability aligns with ATT&CK technique T1018 for Valid Accounts and T1046 for Network Service Scanning, as the vulnerability provides attackers with the means to enumerate internal resources and establish persistence within the network. The flaw particularly threatens enterprise environments where App Studio is used for developing applications that handle sensitive data or integrate with critical internal systems.
Mitigation strategies for this vulnerability must address both immediate remediation and long-term architectural improvements to prevent similar flaws from emerging in future development cycles. Organizations should implement strict input validation for all external request parameters, employing whitelisting mechanisms that only permit connections to pre-approved destinations and protocols. The implementation of network segmentation and firewall rules to restrict outbound connections from application servers represents a crucial defensive measure, while proper authentication and authorization controls should be enforced for all api endpoints. Additionally, organizations should conduct regular security assessments of their application frameworks, implement automated vulnerability scanning, and establish secure coding guidelines that explicitly address SSRF prevention techniques. The vulnerability underscores the importance of following secure development lifecycle practices and demonstrates how seemingly simple api endpoints can create significant security risks when proper input validation and access control mechanisms are not properly implemented.