CVE-2025-2970 in ConcreteCMS
Summary
by MITRE • 03/31/2025
A vulnerability classified as problematic has been found in ConcreteCMS up to 9.3.9. Affected is an unknown function of the component Switch Language Block Handler. The manipulation of the argument Label leads to cross site scripting. It is possible to launch the attack remotely. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
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Analysis
by VulDB Data Team • 03/31/2025
This vulnerability resides within ConcreteCMS version 9.3.9 and earlier, specifically affecting the Switch Language Block Handler component. The issue manifests through an insecure input handling mechanism where the Label argument undergoes insufficient validation or sanitization before being processed and rendered in the web application interface. This represents a classic cross-site scripting vulnerability that allows attackers to inject malicious scripts into web pages viewed by other users.
The technical flaw operates at the input validation layer where user-supplied data enters the application without proper sanitization or encoding. When an attacker crafts a malicious Label argument containing script tags or other malicious payloads, these inputs are directly incorporated into the HTML output without appropriate escaping or encoding mechanisms. This vulnerability falls under the CWE-79 category for Cross-Site Scripting, specifically representing a stored or reflected XSS attack vector depending on how the data is processed and stored within the application's database or session storage.
The operational impact of this vulnerability is significant as it enables remote code execution capabilities through browser-based attacks. An attacker can craft malicious Label values that, when processed by the Switch Language Block Handler, will execute in the context of other users' browsers. This allows for session hijacking, credential theft, defacement of content management interfaces, and potential privilege escalation within the CMS environment. The vulnerability's remote exploitability means that attackers do not require physical access or local network presence to carry out attacks, making it particularly dangerous for widely accessible web applications.
Security practitioners should implement immediate mitigations including input validation and output encoding for all user-supplied data within the Switch Language Block Handler component. The recommended approach involves implementing strict sanitization routines that strip or encode potentially dangerous characters and tags before processing user input. Additionally, content security policies should be enforced to prevent execution of unauthorized scripts. Organizations should also consider implementing web application firewalls that can detect and block malicious payloads targeting this specific vulnerability. The vulnerability's disclosure status indicates that threat actors may already be exploiting this weakness, making immediate remediation critical for maintaining application security posture.
This vulnerability demonstrates the importance of proper input validation and output encoding practices in web application development, aligning with ATT&CK technique T1059.007 for command and script injection. The lack of vendor response despite early disclosure suggests potential gaps in the security community's engagement with open-source projects, highlighting the need for community-driven security monitoring and patching strategies. Organizations using ConcreteCMS should prioritize upgrading to patched versions or implementing compensating controls immediately to protect against exploitation attempts.