CVE-2024-7077: Semtek Sempos Reflected XSS Vulnerability

CVE-2024-7077 Overview

CVE-2024-7077 is a reflected cross-site scripting (XSS) vulnerability in Semtek Sempos, a product developed by Semtek Informatics Software Consulting Inc. The flaw stems from improper neutralization of user-supplied input during web page generation [CWE-79]. An unauthenticated attacker can craft a malicious URL that, when visited by a victim, executes arbitrary JavaScript in the victim's browser session. The issue affects all versions of Semtek Sempos through build 31072024.

Critical Impact
Successful exploitation allows attackers to execute arbitrary script in a victim's browser, enabling session hijacking, credential theft, and unauthorized actions performed under the victim's identity.

Affected Products

Semtek Sempos, all versions up to and including 31072024
Vendor: Semtek Informatics Software Consulting Inc. (semtekyazilim)
Component identifier: semtekyazilim:semtek_sempos

Discovery Timeline

2024-09-04 - CVE-2024-7077 published to the National Vulnerability Database (NVD)
2026-06-17 - Last updated in the NVD database

Technical Details for CVE-2024-7077

Vulnerability Analysis

The vulnerability is a reflected XSS flaw classified under [CWE-79]. Semtek Sempos accepts input through request parameters and reflects that input into the generated HTML response without adequate sanitization or output encoding. Because the injected content is interpreted as executable script by the browser, an attacker can run arbitrary JavaScript in the context of the vulnerable application.

Exploitation requires user interaction. The victim must click a crafted link or visit a page controlled by the attacker that issues the malicious request. The attack originates over the network and does not require authentication or elevated privileges on the target application.

Root Cause

The root cause is missing or incomplete input validation and output encoding in the web page generation logic. Request-supplied values are placed into the HTML response without being escaped according to the surrounding context (HTML body, attribute, JavaScript, or URL). This lets attacker-controlled markup break out of the intended data context and become active script.

Attack Vector

The attack is network-based and reflected. The attacker crafts a URL containing a malicious payload in a vulnerable request parameter and delivers it to the victim through phishing, chat, or a link embedded on a third-party site. When the victim's browser loads the response, the injected script executes with the origin and session context of the Sempos application. Consequences include theft of session cookies, forced actions on behalf of the victim, and delivery of secondary payloads.

No public proof-of-concept, exploit code, or vendor patch URLs are listed in the enriched data. Refer to the Siber Güvenlik Security Advisory and the USOM Incident Notification for advisory context.

Detection Methods for CVE-2024-7077

Indicators of Compromise

Web server access logs containing request parameters with <script>, onerror=, javascript:, or URL-encoded equivalents such as %3Cscript%3E targeting Semtek Sempos endpoints.
Referer headers pointing to external domains immediately preceding suspicious authenticated actions in Sempos.
Unusual outbound requests from user browsers to attacker-controlled domains following a Sempos page load.

Detection Strategies

Deploy a web application firewall (WAF) rule set that inspects query strings and form fields for common XSS payload patterns targeting Sempos URIs.
Enable browser Content Security Policy (CSP) violation reporting to surface injection attempts against Sempos application origins.
Correlate reflected input in HTTP responses against known Sempos parameter names to identify unsanitized reflection points.

Monitoring Recommendations

Ingest Sempos web server and reverse proxy logs into a centralized analytics platform and alert on encoded script markers in request parameters.
Monitor authenticated Sempos sessions for anomalous request sequences that follow inbound clicks from external referers.
Track user reports of unexpected pop-ups, redirects, or session terminations while using the Sempos interface.

How to Mitigate CVE-2024-7077

Immediate Actions Required

Contact Semtek Informatics Software Consulting Inc. to obtain a fixed release beyond build 31072024.
Place a WAF in front of Sempos and enable signatures that block reflected XSS payloads in request parameters.
Instruct users to avoid clicking Sempos links received from untrusted sources until the application is patched.

Patch Information

The enriched data does not include a specific vendor patch URL or fixed version. Organizations should consult the Siber Güvenlik Security Advisory and contact Semtek directly for remediation guidance and updated builds.

Workarounds

Enforce a strict Content Security Policy that disallows inline scripts and restricts script sources to trusted origins.
Set the HttpOnly and Secure flags on session cookies to reduce the impact of script-based cookie theft.
Apply reverse proxy rewrite rules to strip or encode angle brackets and script keywords from Sempos request parameters until a vendor fix is applied.

bash

# Example NGINX rule to block obvious reflected XSS payloads targeting Sempos
location /sempos/ {
    if ($args ~* "(<|%3C)script|javascript:|onerror=|onload=") {
        return 403;
    }
    proxy_pass http://sempos_backend;
}