Description

Unauthenticated Broken Access Control in Chaplin <= 2.6.8 versions.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.5",
  "pubDate": "2026-08-20T12:16:37.817Z",
  "pubdate": "2026-08-20T12:16:37.817Z",
  "executiveSummary": "An unauthenticated broken access control vulnerability has been identified in Chaplin versions up to and including 2.6.8. This security flaw permits remote, unauthenticated threat actors to bypass intended authorization boundaries and access restricted functionality or data resources within the affected application without valid credentials. The vulnerability resides in the core access management logic, which fails to properly validate the authorization state of incoming requests before granting access to sensitive application routes or components. Consequently, successful exploitation of this flaw can lead to unauthorized data exposure, privilege escalation, or unauthorized execution of privileged operations depending on the specific implementation of the Chaplin framework within the target environment. The risk implication is significant as it lowers the attack complexity, allowing malicious actors with network access to the application to compromise confidentiality and integrity without requiring prior system knowledge or user authentication. Mitigation requires immediate attention, specifically updating the affected software to a patched version once available or implementing strict upstream access controls and validation layers at the network or reverse-proxy level to intercept and drop unauthorized requests.",
  "technicalDetails": "The vulnerability stems from insufficient access control enforcement within Chaplin <= 2.6.8, where critical functional components or routing mechanisms fail to properly verify whether an incoming HTTP request originates from an authenticated and authorized entity. In typical web application architectures built upon the Chaplin framework, access control lists (ACLs) or authentication middleware are expected to intercept requests and evaluate session tokens, cookies, or authorization headers. However, due to the identified flaw, these security checks are either omitted, improperly bypassed, or fail to evaluate contextual parameters correctly for specific endpoints.\nFrom an exploitation perspective, an attacker interacts with the network-exposed Chaplin application by crafting direct HTTP requests targeting restricted endpoints, resources, or application states that should normally require valid user sessions or elevated privileges. Because the underlying codebase lacks robust server-side validation or relies solely on client-side state management for authorization decisions, the framework processes the incoming requests and returns the sensitive data or executes the requested actions without demanding proof of authentication.\nThe attack flow proceeds as follows: First, the reconnaissance phase involves the attacker identifying application routes or functional modules managed by the vulnerable Chaplin framework. Second, the exploitation phase executes when the attacker sends unauthenticated HTTP requests (such as GET, POST, PUT, or DELETE) directly to these sensitive endpoints. Third, the post-exploitation impact materializes as the application improperly serves the requested protected resources, allowing unauthorized data exfiltration, exposure of internal application states, or execution of state-changing operations. The vulnerability affects all deployments utilizing Chaplin versions <= 2.6.8 where network exposure allows direct access to unmitigated routes, requiring no specific privileges or specialized payloads beyond standard protocol interaction."
}