CVE-2017-10973 in FineCMS
Summary
by MITRE
In FineCMS before 2017-07-06, application/lib/ajax/get_image_data.php has SSRF, related to requests for non-image files with a modified HTTP Host header.
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Analysis
by VulDB Data Team • 12/12/2022
The vulnerability identified as CVE-2017-10973 affects FineCMS versions prior to 2017-07-06 and resides within the application/lib/ajax/get_image_data.php component. This represents a server-side request forgery vulnerability that allows attackers to make unauthorized requests to internal or external systems through the vulnerable endpoint. The flaw specifically manifests when the application processes requests for non-image files while utilizing a modified HTTP Host header, creating an attack vector that bypasses normal security controls. The vulnerability stems from insufficient input validation and improper handling of HTTP headers, allowing malicious actors to manipulate the application's behavior and potentially access restricted resources.
The technical implementation of this vulnerability involves the application's failure to properly validate or sanitize the HTTP Host header when processing file requests through the get_image_data.php endpoint. When a request is made with a modified Host header for non-image files, the application may inadvertently forward these requests to internal services or external endpoints that it should not be able to access. This behavior aligns with CWE-918, which describes server-side request forgery vulnerabilities where applications make unintended requests to internal resources. The vulnerability can be exploited by crafting HTTP requests with manipulated headers that cause the application to perform requests to internal systems such as databases, internal APIs, or other services that may be accessible from the application server but not from external networks.
The operational impact of this vulnerability extends beyond simple data exfiltration, as it can potentially enable attackers to perform reconnaissance activities against internal network infrastructure. Attackers can leverage this flaw to probe internal services, potentially discovering sensitive systems, misconfigurations, or other vulnerabilities within the internal network. The vulnerability also poses a risk for privilege escalation attacks, as it may allow unauthorized access to internal systems that normally would be protected by network segmentation. According to ATT&CK framework, this vulnerability maps to T1071.004 for application layer protocol: DNS and T1016 for system network configuration discovery, as it enables attackers to explore network topology and potentially gain access to internal resources. The vulnerability can be particularly dangerous in environments where the application server has access to sensitive internal systems, as it provides a pathway for lateral movement and information gathering.
Mitigation strategies for this vulnerability should focus on implementing proper input validation and header sanitization within the affected endpoint. Organizations should ensure that all HTTP headers are properly validated and that the application does not blindly trust or forward requests based on manipulated headers. The recommended approach includes implementing strict validation of file types, requiring proper authentication and authorization checks, and limiting the application's ability to make outbound requests to external systems. Additionally, network segmentation should be implemented to restrict access to internal services, and the application should be updated to the patched version released on 2017-07-06. Security monitoring should be enhanced to detect unusual patterns of outbound requests that may indicate exploitation attempts, and regular security assessments should be conducted to identify similar vulnerabilities in other components of the application. The patch for this vulnerability addresses the root cause by implementing proper validation of the Host header and ensuring that requests are properly filtered based on file type and access permissions.