Description

Subscriber Broken Authentication in User Registration <= 5.2.6 versions.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "5.4",
  "pubDate": "2026-08-18T15:17:08.470Z",
  "pubdate": "2026-08-18T15:17:08.470Z",
  "executiveSummary": "A broken authentication vulnerability has been identified in the User Registration plugin, specifically affecting versions <= 5.2.6. This security flaw introduces significant risk by inadequately handling authentication mechanisms during the registration process, potentially allowing unauthorized actors to compromise user accounts.\nThe vulnerability type is classified as broken authentication, which directly impacts the integrity and confidentiality of user sessions and account data within the affected systems/products. The risk implications are severe, as successful exploitation may enable attackers to bypass security controls, impersonate legitimate users, or gain unauthorized access to privileged functionalities.\nAttacker capabilities in this scenario include the ability to interact with the registration workflow maliciously to subvert standard authentication checks. Depending on the environment configuration, exploitation requirements may involve interacting directly with exposed registration endpoints without requiring prior valid credentials.\nOrganizations utilizing the vulnerable User Registration <= 5.2.6 versions face heightened exposure to account takeover and unauthorized access vectors. Immediate remediation is critical to prevent malicious exploitation and secure the authentication boundary of the application.",
  "technicalDetails": "The vulnerability resides within the user registration and authentication handling components of the User Registration plugin for versions <= 5.2.6. The root cause stems from improper validation and verification of authentication tokens, state parameters, or session identifiers during registration workflows, allowing the logic to be bypassed or manipulated.\nThe vulnerable component handles incoming registration requests and session assignments. Due to insufficient cryptographic checks or flawed logical sequencing, the application fails to adequately authenticate or verify the legitimacy of the user session state, exposing network-accessible endpoints to abuse.\nExploitation occurs over the network where an unauthenticated or low-privileged attacker interacts directly with the vulnerable registration functions. The attack flow typically proceeds as follows: First, the attacker sends a specially crafted registration request to the target endpoint. Second, due to inadequate validation logic within the affected function, the application processes the input without enforcing proper cryptographic verification or session validation constraints. Third, the system incorrectly establishes an authenticated session or registers the user state improperly, granting the attacker unauthorized access or control over user accounts.\nPrivilege requirements for this attack are minimal, as the entry point is exposed to unauthenticated or subscriber-level actors depending on the specific endpoint configuration. The payload behavior involves manipulating parameters within the registration workflow to bypass security gates. Post-exploitation impact includes unauthorized account access, potential privilege escalation if administrative registration workflows are improperly gated, and compromise of sensitive user data managed by the application."
}