CVE-2015-5285 in Kallithea
Summary
by MITRE
CRLF injection vulnerability in Kallithea before 0.3 allows remote attackers to inject arbitrary HTTP headers and conduct HTTP response splitting attacks via the came_from parameter to _admin/login.
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Analysis
by VulDB Data Team • 12/29/2024
The CVE-2015-5285 vulnerability represents a critical CRLF injection flaw in the Kallithea version control system prior to 0.3 release. This vulnerability exists within the authentication handling mechanism, specifically in the way the application processes the came_from parameter during the login process. The flaw allows remote attackers to inject carriage return line feed sequences into HTTP headers, which can lead to severe security implications including HTTP response splitting attacks. The vulnerability is particularly dangerous because it occurs in the administrative login endpoint, making it accessible to any remote attacker without requiring prior authentication.
The technical root cause of this vulnerability stems from insufficient input validation and sanitization of user-supplied parameters. When the came_from parameter is processed during the authentication flow, the application fails to properly escape or filter special characters including carriage return \r and line feed \n sequences. This lack of proper sanitization creates an injection point where malicious actors can insert CRLF sequences that will be interpreted as HTTP header terminators. The vulnerability specifically affects the _admin/login endpoint, which is designed to redirect users to their intended destination after successful authentication, but the parameter handling does not adequately protect against header injection attacks. According to CWE standards, this maps to CWE-113: Improper Neutralization of CRLF Sequences in HTTP Headers, which is a well-documented weakness in web application security.
The operational impact of this vulnerability extends beyond simple header injection, as it enables sophisticated attack vectors including HTTP response splitting, session hijacking, and cross-site scripting exploitation. An attacker can manipulate the HTTP response by injecting malicious headers that may cause the application to redirect to malicious domains or inject content into the response. This can lead to unauthorized access to administrative functions, session fixation attacks, or even complete compromise of the authentication system. The vulnerability is particularly concerning in enterprise environments where Kallithea might be used for code repository management, as it could allow attackers to gain unauthorized access to sensitive source code repositories and administrative controls. The attack surface is broad since the vulnerability is present in the core authentication flow and affects all users attempting to log in through the affected version.
Mitigation strategies for CVE-2015-5285 should focus on immediate patching of the affected Kallithea version to 0.3 or later, which contains the necessary input validation fixes. Organizations should implement proper parameter sanitization and input validation at all points where user-supplied data enters the application, particularly in authentication flows. The recommended approach includes implementing strict character filtering for HTTP header parameters, using established security libraries for input sanitization, and implementing proper output encoding when handling user-provided URLs. Additionally, network-level protections such as web application firewalls can provide additional layers of defense by detecting and blocking suspicious CRLF sequences in HTTP headers. Security monitoring should be enhanced to detect unusual redirect patterns or header injection attempts, and regular security assessments should be conducted to identify similar vulnerabilities in other components of the system. This vulnerability aligns with ATT&CK technique T1190: Exploit Public-Facing Application, highlighting the importance of securing all application endpoints and implementing robust input validation controls across the entire application architecture.