ClassroomIO (<= 1.0.0) - CraftedSignal Threat Feedhttps://feed.craftedsignal.io/products/classroomio--1.0.0/Trending threats, MITRE ATT&CK coverage, and detection metadata. Fed continuously.Hugoenhello@craftedsignal.iohello@craftedsignal.ioThu, 15 Oct 2026 22:50:47 +0000https://feed.craftedsignal.io/favicon-32x32.pngCraftedSignal Threat Feedhttps://feed.craftedsignal.io/3232https://feed.craftedsignal.io/favicon.svgIncorrect Authorization in ClassroomIO Lesson Routeshttps://feed.craftedsignal.io/briefs/2026-10-classroomio-auth-bypass/Thu, 15 Oct 2026 22:50:47 +0000hello@craftedsignal.iohttps://feed.craftedsignal.io/briefs/2026-10-classroomio-auth-bypass/ClassroomIO versions 1.0.0 and earlier contain an authorization flaw in API routes allowing authenticated students to modify or delete arbitrary lesson content across courses.ClassroomIO versions through 1.0.0 contain an incorrect authorization vulnerability that allows authenticated users with standard student privileges to perform unauthorized actions on lesson data. The vulnerability resides in the PUT and DELETE HTTP methods for the '/:lessonId' route. Due to insufficient server-side validation of ownership or authorization, an authenticated student can provide an arbitrary 'lessonId' parameter to modify titles, alter HTML content, or permanently delete lessons. This flaw is not limited to the attacker's own course, as the lack of adequate permission checks allows for cross-course and cross-organization impact. This represents a significant risk to data integrity and course availability for institutions relying on the platform.

Attack Chain

  1. Attacker authenticates to the ClassroomIO platform with valid student credentials.
  2. Attacker intercepts or crafts an HTTP PUT request targeting the /:lessonId endpoint.
  3. Attacker modifies the 'lessonId' parameter in the URL path to point to a target lesson outside of their authorized course.
  4. Attacker injects malicious or destructive content into the request body (e.g., manipulated HTML or empty strings).
  5. The ClassroomIO server fails to validate if the authenticated user has sufficient permissions for the specified 'lessonId'.
  6. The server processes the request and commits the unauthorized modification to the underlying database.
  7. Alternatively, the attacker sends a DELETE request to the /:lessonId endpoint to remove the targeted lesson permanently.
  8. Final objective is the unauthorized alteration or destruction of course curriculum and administrative data.

Impact

Successful exploitation allows for the unauthorized modification or deletion of lesson content, leading to a complete loss of course integrity and availability. Because the vulnerability allows cross-course and cross-organization impact, a single malicious student account can cause widespread disruption to an entire instance or hosting environment.

Recommendation

Prioritize the update or mitigation of affected ClassroomIO instances. Currently, there is no fixed version available; organizations should monitor vendor security communications for patches related to CVE-2026-111369. In the interim, implement strict request filtering on the web application firewall (WAF) to block unauthorized PUT and DELETE methods for the /:lessonId route if they originate from user-level accounts that should not possess administrative privileges.

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