CVE-2019-11274 in Cloud Foundry UAA
Summary
by MITRE
Cloud Foundry UAA, versions prior to 74.0.0, is vulnerable to an XSS attack. A remote unauthenticated malicious attacker could craft a URL that contains a SCIM filter that contains malicious JavaScript, which older browsers may execute.
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Analysis
by VulDB Data Team • 11/23/2023
The Cloud Foundry User Account and Authentication (UAA) system serves as a critical identity management platform for cloud environments, handling user authentication and authorization across distributed applications. Prior to version 74.0.0, this system contained a significant cross-site scripting vulnerability that could be exploited by remote attackers without requiring authentication credentials. This vulnerability specifically affected the SCIM (System for Cross-domain Identity Management) filter processing functionality within the UAA service, creating a dangerous attack vector that could compromise user sessions and potentially escalate privileges within the cloud infrastructure. The flaw existed in how the system handled user input within SCIM filter parameters, particularly when these parameters were processed and rendered in web responses without proper sanitization or encoding.
The technical exploitation of this vulnerability relies on the principle that older web browsers may execute JavaScript code embedded within URL parameters or filter expressions. When a malicious attacker crafts a specially formatted URL containing a SCIM filter with embedded JavaScript payload, the UAA service processes this input and potentially renders it in a web interface without adequate input validation or output encoding. This creates an environment where the malicious script executes in the context of a victim user's browser session, allowing attackers to perform actions such as stealing session cookies, redirecting users to malicious sites, or manipulating web applications. The vulnerability specifically manifests in the way the UAA service handles SCIM filter expressions that contain unescaped or improperly sanitized JavaScript code, making it particularly dangerous in environments where users might interact with the system through web interfaces.
The operational impact of this vulnerability extends beyond simple script execution, potentially enabling more sophisticated attacks within cloud environments. Attackers could leverage this XSS flaw to hijack user sessions, access sensitive user data, or manipulate access controls within the Cloud Foundry environment. The vulnerability affects the integrity of the authentication system, potentially allowing unauthorized access to applications and services protected by the UAA. In multi-tenant cloud environments, this could enable attackers to access other users' data or perform actions on their behalf, creating significant security implications for organizations relying on Cloud Foundry for their infrastructure. The attack surface is particularly concerning given that the vulnerability does not require authentication, making it accessible to anyone who can craft malicious URLs, and the exploitation can occur in older browsers that may not have modern XSS protection mechanisms.
Organizations should prioritize immediate remediation by upgrading to Cloud Foundry UAA version 74.0.0 or later, which includes proper input sanitization and output encoding for SCIM filter parameters. Additional mitigations include implementing Content Security Policy headers to prevent script execution, deploying web application firewalls to detect and block malicious requests, and conducting thorough security testing of all input handling mechanisms within the UAA service. The vulnerability aligns with CWE-79 Cross-site Scripting and can be categorized under ATT&CK technique T1059.007 Command and Scripting Interpreter: JavaScript, demonstrating how web-based applications can be compromised through injection attacks. Regular security assessments of identity management systems and proper input validation practices should be implemented to prevent similar vulnerabilities in other components of the cloud infrastructure. Organizations should also consider implementing monitoring solutions to detect unusual patterns in SCIM filter usage that might indicate exploitation attempts.