CVE-2021-29487 in OctoberCMS
Summary
by MITRE • 08/27/2021
octobercms in a CMS platform based on the Laravel PHP Framework. In affected versions of the october/system package an attacker can exploit this vulnerability to bypass authentication and takeover of and user account on an October CMS server. The vulnerability is exploitable by unauthenticated users via a specially crafted request. This only affects frontend users and the attacker must obtain a Laravel secret key for cookie encryption and signing in order to exploit this vulnerability. The issue has been patched in Build 472 and v1.1.5.
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Analysis
by VulDB Data Team • 09/01/2021
The vulnerability identified as CVE-2021-29487 represents a critical authentication bypass flaw within the October CMS platform, which is built upon the Laravel PHP framework. This issue specifically affects the october/system package and creates a pathway for unauthorized users to gain administrative control over user accounts. The vulnerability's exploitation requires a sophisticated understanding of both the October CMS architecture and the underlying Laravel framework components, making it particularly dangerous for organizations that rely on this content management system for their web presence.
The technical implementation of this vulnerability stems from improper handling of authentication mechanisms within the frontend user authentication flow. Attackers can craft specially designed requests that exploit weaknesses in the session management and cookie validation processes. This flaw allows unauthenticated users to bypass the standard authentication procedures that should normally prevent unauthorized access to user accounts. The vulnerability specifically targets the frontend user authentication system, meaning that while it affects user accounts, it does not directly impact the backend administrative interface. However, successful exploitation can result in complete account takeover and subsequent unauthorized access to user data and privileges.
The operational impact of CVE-2021-29487 extends beyond simple unauthorized access, as it enables attackers to potentially escalate privileges and gain deeper system control. The requirement for a Laravel secret key for cookie encryption and signing adds a layer of complexity to the exploitation process, but also creates a significant risk when such keys are improperly secured or exposed in development environments. Organizations running affected versions of October CMS face potential data breaches, user account compromise, and unauthorized modifications to website content. The vulnerability's impact is particularly severe because it affects the core user authentication system, potentially allowing attackers to impersonate legitimate users and access sensitive information or perform malicious actions within the CMS environment.
The mitigation strategy for this vulnerability requires immediate action from affected organizations to upgrade to patched versions, specifically Build 472 or v1.1.5, which address the underlying authentication bypass mechanism. System administrators should also conduct thorough security audits of their Laravel secret keys and ensure proper key management practices are in place to prevent unauthorized access to encryption materials. Additionally, organizations should implement network-level protections such as web application firewalls and monitoring systems to detect anomalous authentication requests. This vulnerability aligns with CWE-287, which addresses improper authentication issues, and could be categorized under ATT&CK technique T1110 for credential access and T1078 for valid accounts, highlighting the multi-faceted nature of the threat. Regular security updates and proper configuration management become essential practices to prevent exploitation of similar vulnerabilities in the broader October CMS ecosystem.