CVE-2024-23569: HCL Aftermarket EPC XSS Vulnerability

CVE-2024-23569 Overview

CVE-2024-23569 affects HCL Aftermarket EPC, where the server does not configure the X-XSS-Protection HTTP response header. The absence of this header weakens browser-side defenses against reflected cross-site scripting attempts. The vulnerability is categorized under [CWE-692] (Incomplete Denylist to Cross-Site Scripting). Exploitation requires user interaction, such as clicking a crafted link, and can lead to limited disclosure of information rendered in the victim's browser session.

Critical Impact
Missing browser XSS protection headers reduce the effectiveness of client-side filters, increasing exposure to reflected script injection when users interact with attacker-controlled content.

Affected Products

HCL Aftermarket EPC (product line identified by the vendor advisory)

Discovery Timeline

2026-07-17 - CVE-2024-23569 published to NVD
2026-07-17 - Last updated in NVD database

Technical Details for CVE-2024-23569

Vulnerability Analysis

HCL Aftermarket EPC responds to HTTP requests without setting the X-XSS-Protection header. This header historically instructs certain browsers to enable built-in reflected XSS filtering. Without it, browsers that still honor the directive fall back to default behavior, which may allow reflected scripts to execute in a victim's context.

The issue is a security hardening gap rather than an injection flaw itself. Exploitation depends on the presence of a separate reflection vector combined with a browser that respects the header. An attacker must persuade a user to load a crafted URL against a vulnerable EPC instance.

Impact is limited to confidentiality. The vulnerability does not directly allow modification of server data or denial of service. The EPSS score is approximately 0.175%, placing the vulnerability in the lower percentile for near-term exploitation likelihood.

Root Cause

The web server hosting HCL Aftermarket EPC omits the X-XSS-Protection response header from its default configuration. This omission maps to [CWE-692], where a denylist-based control is incomplete because a supporting browser directive is absent.

Attack Vector

An attacker crafts a URL or hosted page that triggers reflected content in the EPC application. The victim, authenticated or not, opens the link. Because the response lacks X-XSS-Protection, browsers that would otherwise block the reflection may render the injected script, leaking session-visible information within the page.

No verified exploit code is available for this vulnerability. See the HCL Software Knowledge Base Article for vendor-provided technical details.

Detection Methods for CVE-2024-23569

Indicators of Compromise

HTTP responses from HCL Aftermarket EPC endpoints that do not include an X-XSS-Protection header
Web server access logs showing crafted query strings containing script tags or JavaScript event handlers directed at EPC URLs
Referrer patterns pointing to attacker-controlled domains preceding requests to EPC application paths

Detection Strategies

Perform HTTP response header audits against all EPC endpoints and flag responses missing X-XSS-Protection
Correlate web application firewall alerts for reflected XSS payloads with EPC hostnames
Monitor browser console error telemetry, where available, for content security policy or script execution anomalies on EPC pages

Monitoring Recommendations

Enable centralized logging of HTTP request and response headers for EPC servers
Baseline expected header sets and alert when security-relevant headers disappear from responses
Review authentication and session activity following user reports of unexpected redirects or content on EPC pages

How to Mitigate CVE-2024-23569

Immediate Actions Required

Apply the vendor guidance published in the HCL Software Knowledge Base Article
Configure the web server or reverse proxy in front of EPC to inject the X-XSS-Protection header on all responses
Add complementary headers such as Content-Security-Policy, X-Content-Type-Options, and Referrer-Policy to strengthen client-side defenses

Patch Information

HCL has published remediation guidance in its knowledge base. Refer to the HCL Software Knowledge Base Article for the current fixed version and configuration steps.

Workarounds

Deploy a reverse proxy rule that appends X-XSS-Protection: 1; mode=block to every response served by EPC
Restrict access to EPC to trusted networks or authenticated users while the header configuration is rolled out
Educate users to avoid clicking untrusted links referencing EPC hostnames until remediation is verified

bash

# Configuration example
# Example nginx directive to add the missing header at the proxy layer
add_header X-XSS-Protection "1; mode=block" always;
add_header X-Content-Type-Options "nosniff" always;
add_header Referrer-Policy "strict-origin-when-cross-origin" always;