Can you explain this vulnerability to me?

[{'type': 'paragraph', 'content': 'CVE-2026-24847 is an open redirect vulnerability found in the Eye Exam form module of the OpenEMR software versions up to 7.0.4. The vulnerability occurs because the application accepts a user-supplied URL parameter and redirects authenticated users to that URL without any validation or sanitization.'}, {'type': 'paragraph', 'content': "Specifically, the vulnerable code takes the 'url' parameter from the request and uses it directly in an HTTP Location header to redirect the user. This allows an attacker to craft URLs that redirect users to arbitrary external sites, potentially malicious ones."}, {'type': 'paragraph', 'content': 'This vulnerability can be exploited by any authenticated user and requires user interaction, such as clicking a crafted link. The issue was fixed in OpenEMR version 8.0.0 by removing the vulnerable redirect code.'}] [1]

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How can this vulnerability impact me? :

This vulnerability can be exploited to perform phishing attacks against healthcare providers using OpenEMR by redirecting them to malicious external websites.

Such phishing attacks can lead to credential theft and unauthorized access to sensitive information.

The vulnerability has a moderate severity with a CVSS score of 6.1, indicating it can be exploited remotely with low complexity and no privileges required, but it does require user interaction.

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How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:

The vulnerability poses risks related to HIPAA compliance because it can facilitate phishing attacks that may lead to unauthorized access or disclosure of protected health information.

By enabling attackers to redirect users to malicious sites, it increases the risk of credential theft and data breaches, which are critical concerns under regulations like HIPAA and GDPR.

Therefore, failing to address this vulnerability could result in non-compliance with these standards due to inadequate protection of sensitive healthcare data.

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How can this vulnerability be detected on my network or system? Can you suggest some commands?

[{'type': 'paragraph', 'content': "This vulnerability can be detected by checking if the OpenEMR instance is running a vulnerable version (prior to 8.0.0) and if the Eye Exam form module's URL redirection is exploitable."}, {'type': 'paragraph', 'content': 'A practical detection method is to authenticate to the OpenEMR system and then attempt to access the vulnerable endpoint with a crafted URL parameter to see if it redirects externally.'}, {'type': 'paragraph', 'content': 'For example, after logging in, you can use a command like the following to test the redirect behavior:'}, {'type': 'list_item', 'content': 'curl -i -L --cookie "<your_auth_cookies>" "http://<openemr_host>:8400/interface/forms/eye_mag/view.php?url=https://evil.com/"'}, {'type': 'paragraph', 'content': 'If the response includes an HTTP 302 redirect to the external URL (e.g., https://evil.com/), the system is vulnerable.'}] [1]

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What immediate steps should I take to mitigate this vulnerability?

The immediate mitigation step is to upgrade OpenEMR to version 8.0.0 or later, where the vulnerable redirect code has been removed.

If upgrading immediately is not possible, consider restricting access to the vulnerable Eye Exam form module or implementing web application firewall (WAF) rules to block requests containing the `url` parameter in the affected endpoint.

Additionally, educate users about phishing risks and monitor for suspicious redirect attempts.

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