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Reflected Cross Site-Scripting (XSS) in Oveleon Cookiebar

Moderate severity GitHub Reviewed Published Jul 26, 2024 in oveleon/contao-cookiebar • Updated Sep 23, 2024

Package

composer oveleon/contao-cookiebar (Composer)

Affected versions

< 1.16.3
>= 2.0.0, < 2.1.3

Patched versions

1.16.3
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

In order to protect businesses against hackers and criminals, we always have to keep our skills and knowledge up to date. Thus, security research is just as important for our work as is building up a security community to promote the exchange of knowledge. After all, more security can only be achieved if many individuals take on the task.

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.

Always for the sake of our mission: "more security."

https://www.usd.de

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.

References

@zoglo zoglo published to oveleon/contao-cookiebar Jul 26, 2024
Published to the GitHub Advisory Database Jul 26, 2024
Reviewed Jul 26, 2024
Published by the National Vulnerability Database Sep 23, 2024
Last updated Sep 23, 2024

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 v4 base metrics

Exploitability Metrics
Attack Vector Network
Attack Complexity Low
Attack Requirements None
Privileges Required None
User interaction Active
Vulnerable System Impact Metrics
Confidentiality None
Integrity None
Availability None
Subsequent System Impact Metrics
Confidentiality Low
Integrity Low
Availability None

CVSS v4 base metrics

Exploitability Metrics
Attack Vector: This metric reflects the context by which vulnerability exploitation is possible. This metric value (and consequently the resulting severity) will be larger the more remote (logically, and physically) an attacker can be in order to exploit the vulnerable system. The assumption is that the number of potential attackers for a vulnerability that could be exploited from across a network is larger than the number of potential attackers that could exploit a vulnerability requiring physical access to a device, and therefore warrants a greater severity.
Attack Complexity: This metric captures measurable actions that must be taken by the attacker to actively evade or circumvent existing built-in security-enhancing conditions in order to obtain a working exploit. These are conditions whose primary purpose is to increase security and/or increase exploit engineering complexity. A vulnerability exploitable without a target-specific variable has a lower complexity than a vulnerability that would require non-trivial customization. This metric is meant to capture security mechanisms utilized by the vulnerable system.
Attack Requirements: This metric captures the prerequisite deployment and execution conditions or variables of the vulnerable system that enable the attack. These differ from security-enhancing techniques/technologies (ref Attack Complexity) as the primary purpose of these conditions is not to explicitly mitigate attacks, but rather, emerge naturally as a consequence of the deployment and execution of the vulnerable system.
Privileges Required: This metric describes the level of privileges an attacker must possess prior to successfully exploiting the vulnerability. The method by which the attacker obtains privileged credentials prior to the attack (e.g., free trial accounts), is outside the scope of this metric. Generally, self-service provisioned accounts do not constitute a privilege requirement if the attacker can grant themselves privileges as part of the attack.
User interaction: This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable system. This metric determines whether the vulnerability can be exploited solely at the will of the attacker, or whether a separate user (or user-initiated process) must participate in some manner.
Vulnerable System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the VULNERABLE SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the VULNERABLE SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the VULNERABLE SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
Subsequent System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the SUBSEQUENT SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the SUBSEQUENT SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the SUBSEQUENT SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N

EPSS score

0.063%
(28th percentile)

Weaknesses

CVE ID

CVE-2024-47069

GHSA ID

GHSA-296q-rj83-g9rq

Source code

Credits

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