CVE-2021-3863 in snipe-it
Summary
by MITRE • 10/19/2021
snipe-it is vulnerable to Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
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Analysis
by VulDB Data Team • 10/23/2021
The CVE-2021-3863 vulnerability affects the snipe-it asset management system and represents a classic cross-site scripting flaw that enables attackers to inject malicious code into web pages viewed by other users. This vulnerability specifically resides in the improper neutralization of input during web page generation processes, making it a prime example of a web application security weakness that can have severe operational consequences. The flaw allows malicious actors to execute arbitrary JavaScript code within the context of a victim's browser session, potentially leading to session hijacking, data theft, or further exploitation of the targeted system.
The technical implementation of this vulnerability stems from insufficient validation and sanitization of user-supplied input that gets rendered directly into web page content without proper escaping or encoding mechanisms. When users interact with snipe-it's web interface and provide input that contains script tags or other malicious payloads, the application fails to adequately neutralize these inputs before incorporating them into dynamically generated HTML content. This failure creates an opening for attackers to inject malicious scripts that execute in the browser context of legitimate users who view affected pages. The vulnerability aligns with CWE-79 which specifically addresses cross-site scripting flaws in web applications and demonstrates how inadequate input validation can lead to persistent security weaknesses in web-based systems.
The operational impact of CVE-2021-3863 extends beyond simple script execution, as it can enable attackers to perform session hijacking attacks, steal sensitive authentication tokens, and potentially escalate privileges within the snipe-it application. An attacker could craft malicious input that, when viewed by an administrator or other privileged user, would execute code to exfiltrate data or establish persistent access to the system. The vulnerability is particularly concerning in enterprise environments where snipe-it is used for asset tracking and management, as it could compromise sensitive inventory data, user credentials, and system configuration information. This type of vulnerability also aligns with ATT&CK technique T1566 which covers social engineering through malicious payloads, and T1071 which addresses application layer protocol usage for command and control communications.
Mitigation strategies for CVE-2021-3863 should focus on implementing robust input validation and output encoding mechanisms throughout the snipe-it application. Organizations should ensure that all user-supplied input undergoes proper sanitization before being rendered in web pages, with special attention to HTML encoding of characters that could be interpreted as markup or script elements. The implementation of Content Security Policy headers can provide additional defense-in-depth measures to prevent execution of unauthorized scripts even if input validation is bypassed. Regular security updates and patches from the snipe-it maintainers should be applied immediately upon release, while also conducting thorough security reviews of application code to identify and remediate similar input handling vulnerabilities. Organizations should also implement proper access controls and monitoring to detect anomalous behavior that might indicate exploitation attempts, and consider network segmentation to limit the potential impact of successful attacks. The vulnerability serves as a reminder of the critical importance of input validation and output encoding in web application security, particularly in systems handling sensitive organizational data.