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usd-2024-0009 | Reflected XSS in Oveleon Cookiebar

Moderate
zoglo published GHSA-296q-rj83-g9rq Jul 26, 2024

Package

No package listed

Affected versions

<1.16.2

Patched versions

1.16.2 || 1.16.3 || 2.1.2 || 2.1.3

Description

usd-2024-0009 | Reflected XSS in Oveleon Cookiebar

Details

Advisory ID: usd-2024-0009
Product: Cookiebar
Affected Version: 2.X
Vulnerability Type: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Security Risk: HIGH, CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N
Vendor URL: https://www.usd.de/
Vendor acknowledged vulnerability: Yes
Vendor Status: Fixed
CVE Number: Not requested yet
CVE Link: Not requested yet
First Published: Published
Last Update: 2024-07-29

Affected Component

The block function in CookiebarController.php.

Desciption

Oveleon's Cookiebar is an extension for the popular Contao CMS.
The block/locale endpoint does not properly sanitize the user-controlled locale input before including it in the backend's HTTP response, thereby causing reflected XSS.

Proof of Concept

The vulnerability could be triggered by entering the following Link:

https://[redacted].de/cookiebar/block/dens82w%22%3E%3Cimg%20src%3da%20onerror%3dalert(1)%3Ew9qt
n/[id]?redirect=https%3A%2F%2F[...]amp%3Biv_load_policy%3D3%26amp%3Bmo
destbranding%3D1%26amp%3Brel%3D0

It is likely related to the following function in the Oveleon Cookiebar source code:

    /**
     * Block content
     *
     * @Route("/cookiebar/block/{locale}/{id}", name="cookiebar_block")
     */
    public function block(Request $request, string $locale, int $id): Response
    {
        System::loadLanguageFile('tl_cookiebar', $locale);

        $this->framework->initialize();

        $objCookie = CookieModel::findById($id);

        if (null === $objCookie || null === $request->headers->get('referer'))
        {
            throw new PageNotFoundException();
        }

        $strUrl = $request->get('redirect');

        // Protect against XSS attacks
        if(!Validator::isUrl($strUrl))
        {
            return new Response('The redirect destination must be a valid URL.', Response::HTTP_BAD_REQUEST);
        }

        $objTemplate = new FrontendTemplate($objCookie->blockTemplate ?: 'ccb_element_blocker');

        $objTemplate->language = $locale;
        $objTemplate->id = $objCookie->id;
        $objTemplate->title = $objCookie->title;
        $objTemplate->type = $objCookie->type;
        $objTemplate->iframeType = $objCookie->iframeType;
        $objTemplate->description = $objCookie->blockDescription;
        $objTemplate->redirect = $request->get('redirect');
        $objTemplate->acceptAndDisplayLabel = $this->translator->trans('tl_cookiebar.acceptAndDisplayLabel', [], 'contao_default', $locale);

        return $objTemplate->getResponse();
    }

Fix

Sanitize the locale input to prevent XSS payloads from being executed in a user's browser.

References

Timeline

  • 2024-04-24: Vulnerability discovered by DR of usd AG.
  • 2024-07-25: Probable cause of the vulnerability has been identified as Oveleon's Cookiebar Extension for Contao CMS.
  • 2024-07-25: Vulnerability disclosed via GitHub Vulnerability Report.

Credits

This security vulnerability was identified by DR of usd AG.

About usd Security Advisories

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Our CST Academy and our usd HeroLab are essential parts of our security mission. We share the knowledge we gain in our practical work and our research through training courses and publications. In this context, the usd HeroLab publishes a series of papers on new vulnerabilities and current security issues.

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Disclaimer

The information provided in this security advisory is provided "as is" and without warranty of any kind. Details of this security advisory may be updated in order to provide as accurate information as possible.

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

CVE ID

CVE-2024-47069

Weaknesses

Credits