How IDOR Still Breaks Applications: The CVE-2024-7041 Example

You would think that by 2024, developers had finally stopped leaving the back door wide open. Yet here we are, with CVE-2024-7041 politely reminding us that “Broken Access Control” isn’t going anywhere. It’s almost like applications enjoy handing out user data as party favors. IDOR (Insecure Direct Object Reference) remains one of those vulnerabilities that shouldn’t exist anymore—and yet it still does, spectacularly.

What is IDOR?

IDOR, short for Insecure Direct Object Reference, occurs when an application exposes internal object identifiers—like database keys, file names, or tokens—without verifying if the requesting user is actually allowed to access them.

Instead of checking “is this user authorized?”, the application naïvely assumes that if you know the object ID, you must be entitled to it.

This is the digital equivalent of leaving your office filing cabinet unlocked because, surely, no one would ever open the wrong drawer.

How IDOR is Introduced

IDORs sneak into applications when developers take shortcuts in access control. Common causes include:

• Predictable identifiers: Sequential numbers or UUIDs passed directly in URLs or API calls.
• Missing server-side checks: Trusting the client’s request without validating ownership.
• Excessive data exposure: APIs returning more information than necessary, allowing attackers to pivot between objects.
• Poor design assumptions: Believing that “hidden” identifiers or obscure endpoints equal security.

In multi-tenant architectures, these mistakes become even more dangerous: a single missing validation can expose data from one organization to another, turning a user-level flaw into a full-blown business disaster.

In the case of CVE-2024-7041, the issue boiled down to insufficient validation on object references, proving once again that “security by optimism” is not a valid strategy.

Risks to the Application and the Business

The risks of IDOR go far beyond a single user peeking at their neighbor’s profile:

• Data leakage: Sensitive personal or financial information becomes accessible.
• Privilege escalation: Attackers may alter parameters to access admin-level resources.
• Account takeover: Manipulating identifiers tied to authentication or session data.
• Business impact: Loss of customer trust, regulatory fines (think GDPR or PCI), brand damage, and revenue loss.

CVE-2024-7041 is a case study in how a single overlooked access check can cascade into legal, financial, and reputational headaches.

Proof of Concept (CVE-2024-7041)

To exemplify this vulnerability we’ll use CVE-2024-7041, present in Open WebUI, a self-hosted interface for AI.

An admin user creates a Memory (a simple note) and the application returns the ID:

The note ID returned is “98b05826-b3f4-4d50-8a0d-404213f93cd5”.

In the attacker account we also create a Memory and capture the update request for that note. The captured request is:

It’s a POST request to:

/api/v1/memories/{id}/update

If we replace {id} with the admin’s Memory ID and resend the same update request, the server accepts it and modifies the admin’s Memory:

Note that I managed to change the other user memory.

Checking the victim (admin) account confirms the change:

This demonstrates that the API applies updates based solely on an object identifier supplied by the client, without verifying ownership — classic IDOR behavior.

Mitigation

Preventing IDOR requires more than crossing your fingers:

• Enforce server-side authorization: Always validate user rights against the resource, never trust client input.
• Use indirect object references: Replace predictable IDs with random, opaque tokens.
• Follow the principle of least privilege: Minimize the amount of data each user can access.
• Add logging and monitoring: Detect suspicious patterns such as sequential ID enumeration.
• Perform security testing: Include automated scans and manual pentesting focused on access control flaws.
• Secure development practices: Code reviews, threat modeling, and security training for developers go a long way.

In other words: stop assuming that just because a user can ask for an object, they should get it.

Conclusion

CVE-2024-7041 proves what many of us already knew: IDORs are like weeds in the security garden—no matter how many times you pull them out, they come back, usually uglier. Applications still fail at the most basic access control checks, as if handing over unauthorized data was a “customer feature.”

If you’re a developer, this is your reminder: don’t let your application make headlines for the wrong reason. Because nothing says “we take your security seriously” like fixing a vulnerability that shouldn’t have existed in the first place.