CVE-2022-24776 is an open redirect vulnerability identified in Flask-AppBuilder, a popular application development framework built on top of the Flask web framework. This vulnerability affects versions of Flask-AppBuilder prior to 3.4.5, specifically when using the database authentication login page. The issue arises because the application improperly validates URL parameters used for redirection after login, allowing an attacker to craft malicious URLs that redirect users to untrusted, potentially malicious external sites. This type of vulnerability is classified under CWE-601 (URL Redirection to Untrusted Site), which can be exploited to facilitate phishing attacks, credential theft, or the delivery of malware by deceiving users into believing they are navigating within a trusted domain. The vulnerability does not require authentication to exploit and does not depend on user interaction beyond clicking a crafted link. Although no known exploits are currently reported in the wild, the presence of this vulnerability in a widely used framework poses a risk to any web applications built on affected versions. The issue was addressed and fixed in version 3.4.5 of Flask-AppBuilder, but no alternative workarounds are available, making patching the primary remediation method.

For European organizations, the open redirect vulnerability in Flask-AppBuilder could have several adverse impacts. Organizations using Flask-AppBuilder to develop internal or customer-facing web applications may inadvertently expose their users to phishing or social engineering attacks, leading to credential compromise or unauthorized access. This risk is particularly significant for sectors with high regulatory requirements such as finance, healthcare, and government, where trust and data confidentiality are paramount. Additionally, successful exploitation could damage organizational reputation and result in compliance violations under regulations like GDPR if personal data is compromised. Since Flask-AppBuilder is often used in enterprise and open-source projects, the scope of affected systems could be broad, including critical infrastructure or services. The vulnerability's exploitation could also serve as a stepping stone for more complex attacks by redirecting users to malicious sites that attempt further exploitation or malware delivery.

The primary and most effective mitigation is to upgrade all Flask-AppBuilder instances to version 3.4.5 or later, where the vulnerability has been patched. Organizations should audit their applications to identify any usage of Flask-AppBuilder versions below 3.4.5, especially those exposing database authentication login pages. In the absence of immediate patching, developers should implement strict validation of redirect URLs, ensuring they only allow redirection to trusted internal domains or use a whitelist approach. Additionally, security teams should monitor web traffic for suspicious redirect patterns and educate users about the risks of clicking on unexpected links. Implementing Content Security Policy (CSP) headers can help limit the impact of malicious redirects by restricting the domains to which browsers can navigate. Finally, integrating multi-factor authentication (MFA) can reduce the risk of credential compromise even if phishing attempts succeed.