Compliance Impact

The provided information does not specify any direct impact or implications of this vulnerability on compliance with common standards and regulations such as GDPR or HIPAA.

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Executive Summary

This vulnerability is a Server-Side Request Forgery (SSRF) issue in the Mercator web application's CVE configuration panel. Specifically, the `testProvider()` method in the ConfigurationController accepts user input and passes it directly to the curl_init() function without validating the URL scheme, hostname, or IP address.

An authenticated user with the configure permission can exploit this flaw to make the Mercator server send arbitrary outbound network requests. The vulnerability allows bypassing URL suffix restrictions by injecting a fragment character (#), giving full control over the target URL.

No restrictions are applied on schemes, hosts, or private/loopback IP addresses. Attackers can use schemes like telnet:// for internal port scanning or gopher:// to interact with unauthenticated internal services such as Redis or Memcached, potentially leading to Remote Code Execution (RCE) under certain deployment conditions.

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Impact Analysis

This vulnerability can have several impacts depending on the deployment environment and attacker capabilities.

• Internal network scanning via the telnet:// scheme, which can reveal open ports and services.
• Out-of-band callbacks allowing attackers to interact with internal or external systems through the vulnerable server.
• Potential Remote Code Execution (RCE) if unauthenticated Redis or Memcached services are accessible from the Mercator host, enabling attackers to inject commands or poison caches.
• Compromise of internal services and data through unauthorized requests initiated by an authenticated user with limited privileges.

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Detection Guidance

Detection of this SSRF vulnerability involves monitoring for unusual outbound network requests originating from the Mercator server, especially those targeting internal services or using uncommon URL schemes such as telnet:// or gopher://.

Since the vulnerability is exploited via the `/admin/config/parameters` endpoint by authenticated users with configure permission, reviewing web server logs for requests to this path with suspicious parameters can help identify exploitation attempts.

Network monitoring tools can be used to detect outbound requests to internal IP ranges or unusual protocols.

• Check web server access logs for POST or GET requests to `/admin/config/parameters` containing URLs with `telnet://`, `gopher://`, or fragment characters (`#`).
• Use network monitoring commands like `tcpdump` or `wireshark` to capture outbound traffic from the Mercator server and filter for unusual schemes or internal IP addresses.
• Example tcpdump command to capture outbound traffic on port 80 or 443: `tcpdump -i eth0 host <Mercator-server-IP> and (port 80 or port 443)`
• Use curl or similar tools to test the vulnerable endpoint with crafted URLs to verify if the server issues outbound requests without validation.

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Mitigation Strategies

The primary mitigation is to upgrade Mercator to version 2025.05.19 or later, where the SSRF vulnerability has been patched.

Until the upgrade can be applied, restrict access to the `/admin/config/parameters` endpoint to only trusted administrators with the configure permission.

Implement network-level controls to block outbound requests from the Mercator server to internal IP ranges and disallow uncommon URL schemes such as telnet:// and gopher://.

Monitor logs for suspicious activity targeting the vulnerable endpoint and unusual outbound network requests.

If possible, disable or restrict access to unauthenticated internal services like Redis or Memcached from the Mercator host to reduce the risk of Remote Code Execution.

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