Insights

Inspectiv Insights - Lessons from Recently Found Vulnerabilities

Written by Inspectiv Team | Apr 27, 2026 7:10:10 PM

Every day, Inspectiv uncovers brand-new vulnerabilities across diverse environments. These findings aren’t theoretical—they’re active weaknesses that attackers would happily exploit today. By learning from fresh discoveries as they emerge, you can harden your systems before adversaries notice.

Below are three high-impact issues recently identified across customer environments, along with the practical defenses your teams can apply immediately. Note some details have been changed for educational purposes.

1 User Access Must Be Revoked Completely, Not Just Disabled Partially

One of the most consistent patterns in March findings was access lingering after it should have been removed completely.

Why it Matters:

In the web application, an “inactive” administrator could still log in and use privileged endpoints to create new admin users, demonstrating how incomplete RBAC enforcement can turn a simple account state change into a privilege escalation or persistent access.

The lesson is that account state must propagate to authorization checks, not just authentication. Many systems disable the login path but leave internal APIs or administrative endpoints accessible that attacks can use to retain or escalate access.

Key takeaway:

  • Disablement must invalidate sessions, tokens, and role permissions
  • RBAC checks must be enforced server-side on every privileged action
  • Treat inactive users as fully unauthenticated, not partially restricted

RBAC systems reduce security risk when they enforce least-privilege role assignments rather than broad permissions tied directly to users.

How to Prevent This:

  1. For disabled users, do not allow any login to the web application
  2. Ensure that inactive users are completely removed from the web application as a best security practice
  3. If login is a must have for inactive users, ensure that sensitive web application functions cannot be accessed - instead redirect back to the main home page

2 Client-Side State Is Not Authentication

Many takeover scenarios emerged from authentication flows trusting values returned to the browser in the form of HTTP responses.

Why it Matters:

In one case, a password-reset flow exposed a URL and token that could be manipulated so an attacker could choose the victim’s phone number and take over the account without verifying ownership. This enabled full account takeover.

Key takeaway:

  • Security state stored in client-visible responses
  • UI flags used as security controls
  • Authentication workflows that can be resumed without re-verification

Key takeaway:

  • Authentication decisions must be enforced server-side and tied to verified identity signals, not UI state.

If a step matters to security, it should be enforced in the backend session or token — never just toggled in the response. Without this step, the function is not secured properly.

How to Prevent This:

  1. Do not include sensitive tokens in any HTTP request responses
  2. Triple check web application logic for security holes
  3. Ensure that HTTP response manipulation does not result in excessive actions being granted

3 File Uploads Are a High-Risk Function

File upload endpoints continue to produce high or critical-impact vulnerabilities, especially when upload locations are web-accessible.

Why It Matters:

File uploads, without the proper controls, have the potential to introduce potentially executable code into sensitive environments.

One finding demonstrated a logo upload endpoint that accepted a disguised ASPX file and executed it on the server, enabling full remote command execution.

Key Takeaway:

These issues often require only small misconfigurations with big results:

Common root causes

  • File type validation based only on file extension
  • Upload directories where scripts are executable
  • Files stored inside the web root
  • Trusting the Content-Type header

Practical mitigation pattern:

  1. Allowlist extensions
  2. Validate file magic bytes
  3. Rename files on upload
  4. Store outside the web root
  5. Disable script execution in upload directories

In many cases, simply restricting file types to images would eliminate the entire attack class.  However it is best to perform defense-in-depth when handling these functions.

How to Prevent This:

  1. Do not allow any form of malicious file upload to web applications
  2. Offload file upload to an external storage service such as Amazon S3
  3. Pass all file uploads to a scanner to check for malicious contents

 

That's it for this edition, but join us next month for more Inspectiv Insights.