CVE-2025-63543: Nooncarlett TechStore XSS Vulnerability

CVE-2025-63543 Overview

CVE-2025-63543 is a reflected Cross-Site Scripting (XSS) vulnerability in TechStore 1.0 by nooncarlett. The flaw resides in the /search_results endpoint and is triggered through the q query parameter. Attackers can inject arbitrary JavaScript that executes in the victim's browser session when a crafted link is opened. The vulnerability is classified under [CWE-79] (Improper Neutralization of Input During Web Page Generation).

Exploitation requires user interaction, typically achieved through phishing links or malicious redirects. Successful attacks enable session hijacking, credential theft, and unauthorized actions performed under the victim's browser context.

Critical Impact
Attackers can execute arbitrary JavaScript in a victim's browser, enabling session token theft and impersonation of authenticated TechStore users.

Affected Products

Nooncarlett TechStore 1.0
CPE: cpe:2.3:a:nooncarlett:techstore:1.0
/search_results endpoint accepting the q parameter

Discovery Timeline

2025-11-07 - CVE-2025-63543 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-63543

Vulnerability Analysis

TechStore 1.0 reflects user-supplied input from the q query parameter back into the search results page without proper output encoding. When a user submits a search query, the application embeds the value directly into the rendered HTML response. This allows an attacker to inject HTML and JavaScript payloads that the browser executes in the security context of the TechStore origin.

Because the attack vector is network-based and requires no authentication, any unauthenticated attacker can craft an exploit URL. The scope change indicated in the CVSS vector reflects that injected script can access resources beyond the vulnerable component, including cookies and DOM elements on the affected domain.

Root Cause

The application fails to sanitize or contextually encode the q parameter before inserting it into HTML output. Standard defenses such as HTML entity encoding, Content Security Policy (CSP), and input validation are either missing or improperly implemented on the /search_results handler.

Attack Vector

An attacker crafts a URL targeting the /search_results endpoint with a malicious JavaScript payload in the q parameter. The attacker then delivers the URL via phishing email, social media, or a malicious third-party site. When the victim clicks the link, TechStore renders the payload inline, and the browser executes the injected script under the TechStore origin. Payloads commonly exfiltrate session cookies, submit forged requests, or inject fake login forms.

Refer to the public proof-of-concept for exploitation details.

Detection Methods for CVE-2025-63543

Indicators of Compromise

HTTP GET requests to /search_results containing <script>, onerror=, javascript:, or encoded variants in the q parameter
Outbound browser requests to unfamiliar domains originating from TechStore pages, indicating cookie or token exfiltration
Web server logs showing unusually long or URL-encoded q values with HTML tag characters

Detection Strategies

Deploy Web Application Firewall (WAF) rules that inspect the q parameter for XSS signatures and reflected content patterns
Enable browser-side CSP violation reporting to surface inline script execution attempts
Correlate access logs with referrer data to identify phishing-driven traffic reaching /search_results

Monitoring Recommendations

Alert on repeated requests to /search_results with encoded HTML characters (%3C, %3E, %22) in the q parameter
Monitor authenticated user sessions for concurrent activity from disparate IP addresses following search requests
Track anomalous JavaScript errors and CSP report-only violations from TechStore application logs

How to Mitigate CVE-2025-63543

Immediate Actions Required

Restrict access to the /search_results endpoint or place TechStore 1.0 behind a WAF with XSS filtering enabled
Notify users to avoid clicking untrusted TechStore search links until a patch is applied
Rotate active session tokens and enforce re-authentication for privileged accounts

Patch Information

No official vendor patch has been published in the NVD record at the time of writing. Monitor the vendor advisory reference and the nooncarlett project repository for remediation updates. Until a fix is available, apply compensating controls to sanitize the q parameter at the proxy or WAF layer.

Workarounds

Implement server-side HTML entity encoding for the q parameter before reflecting it in responses
Deploy a strict Content Security Policy that disallows inline scripts and untrusted script sources
Set the HttpOnly and SameSite=Strict flags on session cookies to reduce impact of successful XSS
Add input validation rejecting non-alphanumeric characters in search queries where feasible

bash

# Example nginx WAF rule to block obvious XSS patterns in q parameter
location /search_results {
    if ($arg_q ~* "(<|%3C).*script.*(>|%3E)") {
        return 403;
    }
    if ($arg_q ~* "(javascript:|onerror=|onload=)") {
        return 403;
    }
    proxy_pass http://techstore_backend;
}