CVE-2025-31970: HCL DFXAnalytics XSS Vulnerability

CVE-2025-31970 Overview

CVE-2025-31970 affects HCL DFXAnalytics due to an insecure security header configuration. The application's Content-Security-Policy (CSP) does not define strict directives for object-src and base-uri. Without these directives, the browser falls back to permissive defaults, weakening defense-in-depth protections against client-side injection attacks. An attacker who finds a separate injection sink can leverage this gap to execute Cross-Site Scripting (XSS) payloads or hijack the document base URI. The weakness is classified under [CWE-358] Improperly Implemented Security Check for Standard.

Critical Impact

The missing CSP directives reduce the browser-side mitigations that would otherwise contain XSS payloads, base-tag hijacking, and plugin-based content injection in HCL DFXAnalytics.

Affected Products

• HCL DFXAnalytics (see vendor advisory for affected versions)

Discovery Timeline

• 2026-05-06 - CVE-2025-31970 published to the National Vulnerability Database (NVD)
• 2026-05-06 - Last updated in NVD database

Technical Details for CVE-2025-31970

Vulnerability Analysis

Content-Security-Policy is an HTTP response header that instructs browsers which sources of content are permitted to load and execute. HCL DFXAnalytics ships a CSP that omits two directives: object-src and base-uri. When object-src is absent, browsers do not inherit the restrictive value from default-src for plugin contexts in older specifications, allowing <object>, <embed>, and <applet> content to load from arbitrary origins. When base-uri is absent, an attacker who injects a <base> tag can rewrite the document base, redirecting relative script and resource loads to attacker-controlled hosts. Both gaps undermine the layered protections that CSP is designed to provide against XSS [CWE-358].

Root Cause

The root cause is a configuration omission in the application's HTTP response headers. The deployed CSP relies on permissive defaults for object-src and base-uri rather than explicitly setting them to 'none' or 'self'. This violates the secure-by-default principle for browser security headers.

Attack Vector

The attack is network-reachable and requires no authentication or user interaction beyond visiting an affected page. Exploitation requires a separate injection primitive in the application. Once an attacker can inject HTML or script content, the missing directives let them load malicious plugin content or override the page base URI to bootstrap further script execution. The vulnerability primarily affects confidentiality of data accessible within the user's browser session.

No public proof-of-concept code is available. Refer to the HCL Software Knowledge Base Article for vendor-supplied technical details.

Detection Methods for CVE-2025-31970

Indicators of Compromise

• HTTP responses from HCL DFXAnalytics that contain a Content-Security-Policy header lacking object-src and base-uri directives.
• Browser console reports or CSP violation reports showing <base> tag insertion or plugin content loads from unexpected origins.
• Outbound web requests from user browsers to domains not associated with the legitimate DFXAnalytics deployment after rendering application pages.

Detection Strategies

• Scan deployed instances with a CSP evaluator and flag any response missing strict object-src 'none' and base-uri 'self' directives.
• Configure CSP report-to or report-uri endpoints to capture violations indicating injection attempts in production.
• Review web proxy and WAF logs for HTML payloads containing <base>, <object>, or <embed> tags submitted to DFXAnalytics endpoints.

Monitoring Recommendations

• Continuously inventory security headers across web applications and alert on regressions in CSP strictness.
• Correlate CSP violation reports with authenticated user sessions to identify targeted users.
• Monitor browser telemetry for unexpected script source origins on DFXAnalytics pages.

How to Mitigate CVE-2025-31970

Immediate Actions Required

• Apply the fix described in the HCL Software Knowledge Base Article once available for your deployment.
• Audit all HCL DFXAnalytics instances for the current Content-Security-Policy header value and document gaps.
• Validate input handling and output encoding throughout the application to remove the underlying injection sinks that CSP is meant to backstop.

Patch Information

HCL has published guidance through its support portal. Administrators should consult the HCL Software Knowledge Base Article for fixed versions, hotfix availability, and configuration steps specific to HCL DFXAnalytics.

Workarounds

• Add object-src 'none' and base-uri 'self' to the CSP at a reverse proxy or web server layer in front of DFXAnalytics until the vendor fix is applied.
• Disable browser plugin content rendering at the network gateway by stripping <object> and <embed> responses where feasible.
• Restrict access to the DFXAnalytics web interface to trusted networks to reduce exposure to opportunistic injection attempts.

# Example reverse proxy header hardening (nginx)
add_header Content-Security-Policy "default-src 'self'; object-src 'none'; base-uri 'self'; frame-ancestors 'self'" always;
add_header X-Content-Type-Options "nosniff" always;
add_header Referrer-Policy "strict-origin-when-cross-origin" always;