Source: cve@mitre.org
Multiple cross-site scripting (XSS) vulnerabilities in cms/front_content.php in Contenido before 4.9.6, when advanced mod rewrite (AMR) is disabled, allow remote attackers to inject arbitrary web script or HTML via the (1) idart, (2) lang, or (3) idcat parameter.
Contenido CMS versions prior to 4.9.6 are vulnerable to multiple cross-site scripting (XSS) attacks, allowing attackers to inject malicious scripts into web pages. This vulnerability can lead to account compromise, data theft, and website defacement by exploiting the idart, lang, and idcat parameters in cms/front_content.php when Advanced Mod Rewrite (AMR) is disabled.
Step 1: Craft Malicious Payload: The attacker crafts a malicious JavaScript payload designed to execute within the victim's browser. This payload could be designed to steal cookies, redirect the user to a phishing site, or perform other malicious actions.
Step 2: Parameter Injection: The attacker injects the crafted payload into the idart, lang, or idcat parameter of the cms/front_content.php script. This is typically done by constructing a specially crafted URL.
Step 3: Request Submission: The attacker sends the malicious URL to the victim, either directly or through social engineering techniques.
Step 4: Server Processing: The Contenido CMS processes the request, including the injected payload within the parameters.
Step 5: Unsanitized Output: The cms/front_content.php script, due to the lack of proper input validation and output encoding, includes the attacker's payload directly in the generated HTML response.
Step 6: Browser Execution: The victim's web browser receives the malicious HTML, including the injected JavaScript payload. The browser then executes the JavaScript, allowing the attacker to perform actions on behalf of the victim.
The vulnerability stems from insufficient input validation and output encoding in the cms/front_content.php script. Specifically, the script fails to properly sanitize user-supplied input from the idart, lang, and idcat parameters before incorporating it into the HTML output. When Advanced Mod Rewrite (AMR) is disabled, the parameters are directly reflected in the rendered HTML without proper escaping, allowing for the injection of malicious JavaScript code. The root cause is a lack of input validation and output encoding (specifically, HTML escaping) of user-supplied parameters. This allows attackers to inject arbitrary HTML and JavaScript into the web page, leading to XSS.
While no specific APTs are directly linked to this CVE, the ease of exploitation makes it a target for various threat actors. The vulnerability could be used as part of a larger attack chain. Not listed on CISA KEV.
Network Intrusion Detection Systems (NIDS) can be configured to detect malicious XSS payloads in HTTP requests, specifically targeting the idart, lang, and idcat parameters in requests to cms/front_content.php.
Web Application Firewalls (WAFs) can be deployed to filter and block malicious XSS payloads before they reach the vulnerable application.
Review web server access logs for suspicious requests containing XSS payloads, such as <script> tags or JavaScript event handlers (e.g., onload, onerror).
Monitor Content Security Policy (CSP) violations, if implemented, to identify attempts to inject and execute unauthorized scripts.
Upgrade to Contenido version 4.9.6 or later.
Implement input validation to sanitize all user-supplied data, ensuring that only expected data types and formats are accepted.
Implement output encoding (e.g., HTML escaping) to properly encode all user-supplied data before it is included in the HTML output.
Enable and configure a Web Application Firewall (WAF) to detect and block XSS attacks.
Implement a Content Security Policy (CSP) to restrict the sources from which the browser can load resources, mitigating the impact of successful XSS attacks.