CVE-2026-79667 in Ech0
Summary
by MITRE • 08/25/2026
Ech0 version 4.3.4 and earlier fails to reliably enforce scoped access token (least-privilege) restrictions on several privileged admin routes. Multiple privileged endpoints (e.g., /api/inbox, /api/panel/comments, /api/backup/export) omit scope checks and authorize based only on the user's admin role, and the backup export handler discards token scope metadata entirely. An attacker holding a deliberately limited (low-scope) admin access token can reach broader privileged functionality than intended, including reading the inbox and exporting a full database backup ZIP archive. Fixed in 4.4.3.
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Analysis
by VulDB Data Team • 08/25/2026
The vulnerability identified in Ech0 versions prior to 4.4.3 represents a critical failure in authorization logic, specifically concerning the enforcement of scoped access tokens within privileged administrative endpoints. This flaw allows an attacker possessing a deliberately restricted or low-scope administrator token to bypass intended security boundaries and execute actions reserved for users with broader privileges. The core technical issue stems from inconsistent implementation of scope validation across different API routes. While some parts of the application correctly verify that the requested action aligns with the permissions granted by the access token, several critical administrative endpoints completely omit these checks. Instead, they rely solely on a binary determination of whether the user holds any form of administrator role, thereby ignoring the specific scopes attached to their authentication credentials. This architectural inconsistency creates a significant gap in the principle of least privilege, which is fundamental to secure application design and identity management systems.
From a technical perspective, the vulnerability manifests primarily through endpoints such as /api/inbox, //api/panel/comments, and /api/backup/export. These routes are designed to handle sensitive administrative tasks but fail to inspect the scope metadata embedded within the bearer token presented by the client. In particular, the handler for database backup exports exhibits a severe logic error where it discards token scope information entirely during processing. Consequently, any user authenticated as an administrator, regardless of how narrowly their permissions were defined at issuance, gains unrestricted access to these functions. This allows low-privilege administrators to perform high-risk operations that should be strictly prohibited under normal operational policies, effectively elevating their capabilities beyond what was intended by the system's security model.
The operational impact of this vulnerability is substantial and poses severe risks to data confidentiality and integrity. An attacker exploiting this flaw can access sensitive internal communications via the inbox endpoint, potentially exposing private organizational discussions or confidential user data. More critically, the ability to export a full database backup archive through the compromised backup handler enables the exfiltration of vast amounts of structured data. This includes user credentials, personal identifiable information, configuration settings, and other critical system state data. The availability of a complete database dump significantly amplifies the potential for downstream attacks, including credential stuffing, social engineering based on harvested data, or further exploitation of internal systems using leaked secrets.
This vulnerability aligns with CWE-269, which describes Improper Privilege Control, as it involves an actor obtaining privileges they are not authorized to have due to a failure in the system's access control mechanisms. Furthermore, from the perspective of the MITRE ATT&CK framework, this behavior is consistent with T1078, Valid Accounts, specifically when combined with privilege escalation techniques where legitimate credentials are used to bypass restrictions. The exploitation does not require complex injection or buffer overflow exploits but rather relies on simple HTTP requests using a valid token that lacks sufficient scope checks by the server-side logic.
Mitigation for this issue is straightforward and has already been addressed in Ech0 version 4.4.3, which should be deployed immediately to remediate the flaw. For organizations unable to upgrade instantly, temporary mitigations involve implementing reverse proxy rules or WAF policies that restrict access to the affected endpoints based on additional verification layers not present in the application code itself. However, relying on external controls is less robust than fixing the root cause within the application logic. Developers must ensure that all administrative routes perform rigorous scope validation against the claims contained in the JWT or OAuth token before processing any request. This includes auditing all API handlers to guarantee consistent enforcement of least-privilege principles across the entire administration interface, ensuring that role-based access control is always supplemented by attribute-based checks where necessary.