CVE-2010-2429 in Splunk
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in Splunk 4.0 through 4.1.2, when Internet Explorer is used, allows remote attackers to inject arbitrary web script or HTML via the HTTP Referer in a "404 Not Found" response.
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Analysis
by VulDB Data Team • 09/18/2021
The vulnerability identified as CVE-2010-2429 represents a critical cross-site scripting flaw affecting Splunk versions 4.0 through 4.1.2 when operating in Internet Explorer environments. This vulnerability specifically exploits the way Splunk handles HTTP Referer headers in error responses, creating an avenue for remote attackers to execute malicious scripts within the context of a victim's browser session. The issue is particularly concerning as it leverages the trust relationship between the browser and the web application, allowing attackers to inject arbitrary web script or HTML code that executes when users navigate to affected pages.
The technical flaw resides in Splunk's improper sanitization of the HTTP Referer header within its error handling mechanism. When a user attempts to access a non-existent resource resulting in a "404 Not Found" response, the system fails to adequately filter or escape the Referer header content before rendering it in the error page. This omission creates a classic XSS vulnerability where attacker-controlled data flows directly into the browser's rendering engine without proper input validation or output encoding. The vulnerability is specifically triggered when Internet Explorer processes the malformed response, making it particularly dangerous in enterprise environments where IE remains prevalent. This behavior aligns with CWE-79, which defines cross-site scripting as the improper handling of potentially malicious input data that gets executed in a user's browser context.
The operational impact of this vulnerability extends beyond simple script injection, as it provides attackers with the capability to perform session hijacking, steal sensitive information, redirect users to malicious websites, or even execute more sophisticated attacks such as credential theft. In a corporate environment where Splunk is commonly used for log aggregation and security monitoring, this vulnerability could allow attackers to compromise the integrity of the security infrastructure itself. The attack vector is particularly insidious because it requires no authentication or privileged access, making it accessible to any remote user who can craft a malicious Referer header and trigger the error condition. This vulnerability directly maps to ATT&CK technique T1566.001, which covers the use of malicious web content to gain initial access through phishing or other social engineering methods.
Organizations should immediately implement mitigations including upgrading to Splunk versions that address this vulnerability, typically 4.1.3 or later, which include proper input sanitization for Referer headers. Additionally, administrators should consider implementing web application firewalls that can detect and block suspicious Referer header patterns, though this represents a defensive measure rather than a complete solution. Network-level protections such as intrusion detection systems configured to monitor for malicious Referer headers may provide additional defense in depth. The vulnerability also underscores the importance of proper input validation and output encoding practices as outlined in the OWASP Top Ten security principles, specifically addressing the need for robust sanitization of all user-controllable inputs. Organizations should conduct thorough security assessments of their Splunk deployments to ensure no other similar vulnerabilities exist within their logging and monitoring infrastructure.