CVE-2018-18837 in Netdata
Summary
by MITRE
An issue was discovered in Netdata 1.10.0. HTTP Header Injection exists via the api/v1/data filename parameter because of web_client_api_request_v1_data in web/api/web_api_v1.c.
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Analysis
by VulDB Data Team • 02/03/2025
The vulnerability identified as CVE-2018-18837 represents a critical HTTP header injection flaw within the Netdata monitoring platform version 1.10.0. This issue resides in the web API component where user-supplied input is not properly sanitized before being incorporated into HTTP response headers. The specific affected function web_client_api_request_v1_data in web/api/web_api_v1.c demonstrates poor input validation practices that allow attackers to inject malicious content into HTTP headers, potentially enabling various attack vectors including cache poisoning, session manipulation, and cross-site scripting exploitation. The vulnerability stems from the improper handling of the filename parameter within the api/v1/data endpoint, which serves as a critical interface for data retrieval and monitoring operations.
The technical exploitation of this vulnerability occurs when an attacker crafts malicious input containing special characters or header injection sequences that get processed and included in HTTP response headers without adequate sanitization. This flaw falls under CWE-113, which specifically addresses improper neutralization of CRLF (Carriage Return Line Feed) characters in HTTP headers, making it susceptible to header injection attacks. The impact extends beyond simple header manipulation as it can enable attackers to manipulate the behavior of web applications and browsers that rely on these headers for proper operation. The vulnerability affects the core data retrieval functionality of Netdata, potentially compromising the integrity of monitoring data and exposing the system to further attacks that leverage the injected headers.
Operational consequences of this vulnerability are significant for organizations relying on Netdata for system monitoring and alerting. Attackers could exploit this weakness to inject malicious headers that redirect users to phishing sites, manipulate caching mechanisms to serve poisoned content, or inject script tags that could execute in the context of legitimate user sessions. The vulnerability also creates potential for session hijacking attacks where attackers might manipulate authentication headers or cookies that are processed through the affected API endpoint. Organizations using Netdata in production environments face risks of data integrity compromise and potential unauthorized access to monitoring systems that could go undetected for extended periods. The exposure is particularly concerning given that Netdata is commonly deployed in critical infrastructure monitoring scenarios where maintaining the integrity of monitoring data is paramount for security operations.
Mitigation strategies should focus on immediate patching of the Netdata software to version 1.10.1 or later where the vulnerability has been addressed through proper input sanitization and validation. Organizations should implement network-level monitoring to detect unusual header injection patterns and establish robust input validation policies for all API endpoints. The fix typically involves implementing strict sanitization of user-supplied parameters before they are processed or included in HTTP headers, using techniques such as escaping special characters, implementing allowlists for valid input patterns, and employing proper header encoding mechanisms. Additionally, organizations should conduct comprehensive security reviews of their API implementations to identify similar vulnerabilities in other components and establish automated testing procedures that include header injection testing as part of their security validation processes. The remediation should align with ATT&CK technique T1071.004 for application layer protocol: DNS to ensure proper handling of network communication protocols and prevent similar injection vulnerabilities in the broader attack surface.