CVE-2025-31117: OpenEMR SSRF Vulnerability

CVE-2025-31117 Overview

CVE-2025-31117 is an Out-of-Band Server-Side Request Forgery (OOB SSRF) vulnerability in OpenEMR, an open source electronic health records and medical practice management application. The flaw allows an unauthenticated attacker to coerce the OpenEMR server into issuing unauthorized HTTP or DNS requests to attacker-controlled or internal resources. Because the response is not returned directly to the attacker, exploitation relies on out-of-band channels such as DNS lookups or HTTP callbacks to exfiltrate sensitive data. The vulnerability is tracked under [CWE-918] and is fixed in OpenEMR version 7.0.3.1.

Critical Impact

An unauthenticated remote attacker can pivot the OpenEMR server into internal networks, probe internal services, and exfiltrate sensitive information through out-of-band channels.

Affected Products

• OpenEMR versions prior to 7.0.3.1
• Self-hosted OpenEMR deployments exposed to untrusted networks
• Containerized OpenEMR instances running vulnerable releases

Discovery Timeline

• 2025-03-31 - CVE-2025-31117 published to NVD
• 2025-04-30 - Last updated in NVD database

Technical Details for CVE-2025-31117

Vulnerability Analysis

The vulnerability is a Server-Side Request Forgery flaw classified under [CWE-918]. OpenEMR accepts attacker-influenced input that is subsequently used by the server to issue outbound network requests. Because no validation or allowlisting restricts the destination of these requests, an attacker can direct OpenEMR to contact arbitrary hosts. The server does not return the response body to the client, making this an out-of-band variant. Attackers confirm exploitation by observing DNS queries or HTTP callbacks on infrastructure they control. The flaw is network-reachable and requires no authentication or user interaction.

Root Cause

The root cause is missing validation of user-supplied URLs or hostnames before OpenEMR initiates server-side network requests. Without an allowlist of permitted destinations or sanitization of host and scheme components, the application forwards requests to any address the attacker supplies, including internal RFC1918 addresses, cloud metadata endpoints, and external attacker infrastructure.

Attack Vector

The attack is launched over the network against an exposed OpenEMR endpoint that processes attacker-supplied URLs. The attacker injects a hostname pointing to a DNS or HTTP listener under their control. When OpenEMR resolves and connects to that host, the attacker records the interaction. The same primitive can be redirected against internal services to enumerate the network, reach cloud metadata APIs, or stage data exfiltration. No verified public proof-of-concept code is available; see the GitHub Security Advisory GHSA-2pvv-ph3x-2f9h for technical details.

Detection Methods for CVE-2025-31117

Indicators of Compromise

• Outbound DNS queries from the OpenEMR host to unfamiliar domains, particularly common SSRF canary services or attacker-controlled subdomains
• Outbound HTTP or HTTPS connections from OpenEMR application processes to RFC1918 ranges or cloud metadata endpoints such as 169.254.169.254
• Unexpected egress traffic originating from the PHP or web server process running OpenEMR

Detection Strategies

• Inspect web server access logs for requests containing URL parameters with external or internal hostnames, IP literals, or non-HTTP schemes
• Correlate inbound HTTP requests to OpenEMR with subsequent outbound DNS or HTTP traffic from the same host within a short time window
• Deploy egress monitoring that flags any outbound connection from the OpenEMR server to destinations outside an approved allowlist

Monitoring Recommendations

• Forward OpenEMR application logs, web server logs, and DNS resolver logs to a centralized SIEM for correlation
• Alert on connections from OpenEMR hosts to cloud instance metadata endpoints and link-local addresses
• Track the OpenEMR version banner across deployments to identify hosts still running releases prior to 7.0.3.1

How to Mitigate CVE-2025-31117

Immediate Actions Required

• Upgrade OpenEMR to version 7.0.3.1 or later, which contains the official fix
• Restrict outbound network access from OpenEMR servers to only the destinations required for normal operation
• Block OpenEMR hosts from reaching cloud metadata services and internal management networks at the firewall layer

Patch Information

The vulnerability is fixed in OpenEMR 7.0.3.1. The upstream code change is documented in the OpenEMR GitHub commit aa6f50e and the GitHub Security Advisory GHSA-2pvv-ph3x-2f9h. Administrators should apply the patched release rather than attempting to backport individual changes.

Workarounds

• Place OpenEMR behind a reverse proxy or web application firewall configured to strip or validate URL-bearing parameters
• Configure host-level egress filtering to permit only required outbound destinations from the OpenEMR application server
• Disable or restrict OpenEMR features that fetch remote resources until the patched version can be deployed

# Example iptables egress restriction for an OpenEMR host
# Block access to cloud metadata and RFC1918 ranges from the web user
iptables -A OUTPUT -m owner --uid-owner www-data -d 169.254.169.254 -j DROP
iptables -A OUTPUT -m owner --uid-owner www-data -d 10.0.0.0/8 -j DROP
iptables -A OUTPUT -m owner --uid-owner www-data -d 172.16.0.0/12 -j DROP
iptables -A OUTPUT -m owner --uid-owner www-data -d 192.168.0.0/16 -j DROP