The App Builder – Create Native Android & iOS Apps On The Flight plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to and including 5.6.0. This vulnerability allows attackers to exploit the upload_avatar() function, as it lacks necessary authorization validation. Specifically, it accepts an attacker-controlled user_id parameter from the POST request body and uses it to update user meta without verification.
This oversight enables authenticated attackers, with Subscriber-level access and above, to overwrite the profile avatar of any arbitrary user on the site, including administrators. To execute this attack, the attacker must supply a target user_id in the request body to the /wp-json/app-builder/v1/upload-avatar endpoint.
The CVSS score for this vulnerability is 5.3, which indicates a medium severity level. Organizations utilizing this plugin should understand that the risk to organizations includes potential unauthorized changes to user profiles, which could lead to further exploitation.
Given the nature of this vulnerability and its potential impact, organizations should prioritize patching immediately.
Vulnerability Details
The vulnerability is classified as Insecure Direct Object Reference (IDOR), represented by CWE-639. The affected product is the App Builder plugin for WordPress, with the latest affected version being 5.6.0.
The vulnerability was published on May 2, 2026. The attack vector is network-based, and the attack complexity is low, meaning that exploiting this vulnerability does not require significant technical skills.
Technical Analysis
The root cause of this vulnerability lies in the absence of proper authorization checks within the upload_avatar() function. The function accepts a user_id parameter without validating the requestor's rights to modify the user profile. This lack of checks allows an authenticated user to change the profile avatar of any user, including those with elevated permissions.
The attack vector is network-based, requiring minimal complexity. Attackers need no special privileges, and user interaction is not necessary to exploit this vulnerability, making it accessible for attackers with only Subscriber-level access.
The impact of this vulnerability on confidentiality is none, while the impact on integrity is low, allowing unauthorized changes to user avatars. There is no impact on availability.
Risk & Impact Analysis
Risk to organizations includes the potential for unauthorized changes to user profiles, which can lead to reputational damage and loss of user trust. The vulnerability's medium severity indicates that it should be addressed promptly within the organization's patch management cycle.
The blast radius of this vulnerability is significant due to the possibility of affecting any user within the system, including those with administrative privileges. Organizations should schedule remediation as part of their security update processes.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
All versions prior to the vendor patch are affected, specifically up to and including version 5.6.0 of the App Builder plugin for WordPress.
Mitigation & Remediation
Organizations should promptly update the App Builder plugin to version 5.6.1 or later to mitigate this vulnerability. If a patch is unavailable, consider implementing workarounds such as limiting access to the affected REST API endpoint and enhancing authentication checks.
Regular monitoring for any unauthorized changes to user profiles is also recommended. Additionally, implementing configuration hardening measures can help to minimize exposure to similar vulnerabilities in the future.
For more information on effective security practices, organizations can refer to the vulnerability management program.
Detection Guidance
Security teams should monitor logs for indicators of unauthorized requests to the /wp-json/app-builder/v1/upload-avatar endpoint. Behavioral anomalies or changes in user profile avatars should be flagged for review.
AppSecure Threat Intelligence Insight
This vulnerability highlights the importance of validating user permissions for sensitive operations within applications. Security teams should regularly audit their systems for similar issues and ensure that proper authorization checks are implemented.
For more insights, organizations can explore our resources on privilege escalation and best practices in penetration testing methodology.
By staying informed and proactive, organizations can better defend against similar vulnerabilities in the future.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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