CVE-2016-3691 in Kallithea
Summary
by MITRE
Routes in Kallithea before 0.3.2 allows remote attackers to bypass the CSRF protection by using the GET HTTP request method.
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Analysis
by VulDB Data Team • 09/20/2020
The vulnerability identified as CVE-2016-3691 affects Kallithea versions prior to 0.3.2, representing a critical security flaw in the web application's cross-site request forgery protection mechanisms. This issue stems from the application's improper handling of HTTP request methods, specifically allowing unauthorized users to circumvent security controls designed to prevent malicious actions. The vulnerability exists within the routing logic of the application where GET requests are not properly validated against CSRF protection measures that should typically be enforced for all HTTP methods.
The technical flaw manifests when remote attackers exploit the application's routing system to perform CSRF attacks using GET requests instead of the more secure POST or PUT methods. This bypass occurs because the application's CSRF protection mechanism fails to properly validate the request method, allowing attackers to construct malicious URLs that can trigger unintended actions within the application's context. The vulnerability represents a design flaw in the security architecture where the application assumes that all requests should be validated regardless of method type, but the implementation does not enforce this validation properly.
Operationally, this vulnerability poses significant risks to organizations using affected Kallithea versions, as it allows remote attackers to perform unauthorized actions on behalf of authenticated users without requiring them to be logged in. Attackers can craft specially crafted URLs that, when visited by an authenticated user, execute malicious operations such as creating new repositories, modifying user permissions, or accessing sensitive data. The impact extends beyond simple data manipulation to potentially allow complete compromise of user accounts and system integrity, particularly when combined with other vulnerabilities or social engineering techniques.
The vulnerability aligns with CWE-352, which specifically addresses Cross-Site Request Forgery weaknesses in web applications, and demonstrates a failure to implement proper request validation mechanisms. From an ATT&CK perspective, this vulnerability maps to T1566.001 - Phishing: Spearphishing Attachment, where attackers can exploit the CSRF bypass to deliver malicious payloads through crafted links. The flaw also relates to T1071.004 - Application Layer Protocol: DNS, as attackers may use DNS-based techniques to deliver malicious URLs that exploit this vulnerability. Organizations should immediately update to Kallithea version 0.3.2 or later to remediate this issue, and implement additional monitoring to detect unusual GET request patterns that may indicate exploitation attempts. Network segmentation and web application firewalls can provide additional defense-in-depth measures while waiting for the official patch deployment.