Description

The Mang Board WP plugin for WordPress is vulnerable to Missing Authorization via Authentication Cookie Forgery in all versions up to, and including, 2.3.7. This is due to flawed HMAC generation in the mbw_get_hash_key() function that uses the current user's identity instead of the cookie username parameter when a WordPress user is logged in, combined with insufficient validation in mbw_validate_auth_cookie(). This makes it possible for authenticated attackers, with subscriber-level access and above, to forge administrator authentication cookies and change administrator passwords to achieve complete site takeover.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.8",
  "pubDate": "2026-08-26T08:16:46.383Z",
  "pubdate": "2026-08-26T08:16:46.383Z",
  "executiveSummary": "The Mang Board WordPress plugin (versions 2.3.7 and below) contains a critical Missing Authorization vulnerability stemming from flawed HMAC generation logic.\nThe vulnerability allows an authenticated attacker, holding a minimum privilege level of Subscriber, to perform Authentication Cookie Forgery.\nBy manipulating the authentication process, an attacker can impersonate an Administrator, ultimately leading to a complete site takeover.\nThe root cause lies in the improper implementation of the mbw_get_hash_key() function, which incorrectly references the current user's session identity rather than the provided cookie username parameter during HMAC validation.\nThis flaw, combined with insufficient validation within the mbw_validate_auth_cookie() function, creates a bypass mechanism for existing session security controls.\nThe risk is categorized as critical because it facilitates full administrative privilege escalation, allowing the attacker to modify site configurations, delete content, or alter administrative account credentials. Exploitation requires existing authenticated access to the target WordPress installation.",
  "technicalDetails": "The vulnerability originates from a logical flaw in how the Mang Board plugin generates and validates authentication cookies. Specifically, the mbw_get_hash_key() function is designed to generate a hash key used for verifying the integrity and authenticity of user sessions. However, the implementation incorrectly utilizes the identity of the currently logged-in user rather than the specific username parameter passed within the authentication cookie.\nWhen a user triggers an authentication event, the plugin's mbw_validate_auth_cookie() function attempts to verify the provided cookie. Because mbw_get_hash_key() relies on the wrong data source, the resulting HMAC is predictably generated based on the attacker's own session context or insufficient session entropy. This leads to a scenario where the application accepts a forged cookie as legitimate because it fails to perform a cryptographically secure, context-aware validation.\nThe attack flow proceeds as follows: First, a malicious actor with a Subscriber-level account initiates a crafted request that simulates the administrative cookie structure expected by the plugin. Due to the flawed logic in mbw_get_hash_key(), the application validates this forged cookie by comparing it against an improperly derived key.\nBecause the validation mechanism in mbw_validate_auth_cookie() does not strictly enforce the integrity of the cookie parameters against the server-side state, the attacker successfully bypasses authorization checks. Once the forged cookie is accepted, the plugin grants the attacker the privileges associated with the identity encoded in the forged token, typically that of an Administrator.\nUpon successful elevation to an administrative state, the attacker gains full control over the site's back-end functionality. This includes the capability to change the administrator's password, modify WordPress core or plugin settings, install malicious code, or exfiltrate sensitive database information. The exposure is network-based, necessitating access to the web interface where the plugin is active, but the exploitation is strictly confined to the application layer logic rather than requiring external network vulnerabilities.\nThe affected component is the plugin's internal authentication handling logic. Versions up to and including 2.3.7 are confirmed vulnerable. The primary failure is the lack of proper binding between the user identity and the HMAC key generation process, allowing for deterministic hash collision or outright bypass of the signature verification routine."
}