CVE-2017-16244 in October
Summary
by MITRE
Cross-Site Request Forgery exists in OctoberCMS 1.0.426 (aka Build 426) due to improper validation of CSRF tokens for postback handling, allowing an attacker to successfully take over the victim's account. The attack bypasses a protection mechanism involving X-CSRF headers and CSRF tokens via a certain _handler postback variable.
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Analysis
by VulDB Data Team • 09/24/2025
The vulnerability identified as CVE-2017-16244 represents a critical cross-site request forgery flaw discovered in OctoberCMS version 1.0.426, also known as Build 426. This vulnerability resides within the framework's postback handling mechanism and specifically targets the validation of CSRF tokens that are intended to protect against unauthorized actions performed on behalf of authenticated users. The flaw allows attackers to bypass existing security protections by exploiting a specific weakness in how the system validates tokens during postback operations.
The technical implementation of this vulnerability stems from improper validation of CSRF tokens within the OctoberCMS framework's request processing pipeline. When users interact with the CMS through web forms or AJAX requests, the system typically employs CSRF tokens to ensure that requests originate from legitimate sources and that users have authorized the actions being performed. However, in version 1.0.426, the framework fails to properly validate these tokens when processing certain postback operations involving the _handler variable. This variable serves as a mechanism for handling specific AJAX callbacks and form submissions within the CMS architecture, and its improper handling creates a pathway for attackers to forge requests that appear to be legitimate user actions.
The operational impact of this vulnerability is severe as it enables attackers to completely compromise user accounts without requiring authentication credentials. An attacker can craft malicious requests that exploit the CSRF vulnerability to perform actions such as changing user passwords, modifying account settings, or executing administrative functions within the compromised user's session. The attack bypasses the standard X-CSRF headers protection mechanism, which typically provides an additional layer of security by requiring the presence of specific headers in legitimate requests. This bypass occurs because the vulnerability specifically targets the _handler postback variable, which allows attackers to manipulate the request flow in a way that circumvents the normal token validation procedures.
The flaw aligns with CWE-352, which defines Cross-Site Request Forgery vulnerabilities as a critical security weakness that allows attackers to perform actions on behalf of authenticated users without their knowledge or consent. This vulnerability also maps to ATT&CK technique T1566.001, which describes the use of credential stuffing and session hijacking techniques to gain unauthorized access to user accounts. The exploitation of this vulnerability demonstrates a sophisticated understanding of how web application frameworks handle authentication tokens and session management, particularly in AJAX-driven environments where traditional CSRF protection mechanisms may be insufficient.
Organizations using OctoberCMS 1.0.426 should immediately implement mitigations including updating to a patched version of the framework, implementing additional validation controls for the _handler postback variable, and strengthening the overall CSRF protection mechanisms. Security measures should include enhanced token validation procedures, mandatory header checks for all critical operations, and comprehensive monitoring of postback requests. The vulnerability highlights the importance of thorough testing of authentication mechanisms and the need for robust protection against session manipulation attacks, particularly in content management systems where user privileges can be leveraged to cause significant damage to web applications and their underlying data.