CVE-2022-21651 is an open redirect vulnerability identified in Shopware, an open source e-commerce platform widely used for building online shops. The vulnerability arises from incomplete URL handling within the Shopware router component, which allows attackers to craft URLs that redirect users to arbitrary, potentially malicious external websites. This type of vulnerability is classified under CWE-601 (URL Redirection to Untrusted Site). The affected versions include all Shopware releases from 5.0.0 up to, but not including, 5.7.7, where the issue has been fixed. The vulnerability does not require authentication or user privileges to exploit, but it does rely on user interaction, as victims must click on a maliciously crafted link. Although no known exploits have been reported in the wild, the risk lies in attackers leveraging the open redirect to facilitate phishing attacks, credential theft, or distribution of malware by redirecting unsuspecting users to harmful sites. The lack of a workaround means that the only effective remediation is upgrading to Shopware version 5.7.7 or later. Given the nature of the vulnerability, it primarily impacts the confidentiality and integrity of user sessions by enabling social engineering attacks, while the availability of the Shopware platform itself remains unaffected.

For European organizations using Shopware versions prior to 5.7.7, this vulnerability poses a significant risk primarily through social engineering vectors. Attackers can exploit the open redirect to deceive customers into visiting malicious websites, potentially leading to credential compromise, fraud, or malware infections. This can damage brand reputation, erode customer trust, and result in financial losses. E-commerce platforms are critical infrastructure for many European businesses, especially SMEs relying on online sales. The vulnerability could also be leveraged in targeted phishing campaigns against employees or partners, increasing the risk of broader network compromise. While the vulnerability does not directly compromise Shopware server integrity or availability, the indirect effects on confidentiality and trust can be substantial. Organizations in sectors with strict data protection regulations, such as finance, healthcare, and retail, may face compliance risks if customer data is compromised due to exploitation of this vulnerability.

1. Immediate upgrade to Shopware version 5.7.7 or later is essential, as this is the only available fix. 2. Implement strict URL validation and sanitization on any custom modules or integrations that handle redirects to prevent exploitation of similar issues. 3. Employ web application firewalls (WAFs) with rules designed to detect and block suspicious redirect patterns associated with this vulnerability. 4. Conduct user awareness training focused on recognizing phishing attempts that may exploit open redirects. 5. Monitor web server logs for unusual redirect activity or spikes in traffic to external URLs that could indicate exploitation attempts. 6. For organizations unable to upgrade immediately, consider temporarily disabling or restricting features that perform redirects based on user input, if feasible. 7. Review and harden email filtering policies to reduce the likelihood of phishing emails reaching end users that leverage this vulnerability.