CVE-2022-47409 is a vulnerability identified in the fp_newsletter extension for TYPO3, a popular open-source content management system widely used for building and managing websites. The fp_newsletter extension manages newsletter subscriptions and subscriber data. The vulnerability affects multiple versions of the extension prior to 1.1.1, 1.2.0, 2.x before 2.1.2, 2.2.1 through 2.4.0, and 3.x before 3.2.6. The core issue lies in the deleteAction operation, which processes subscription UIDs (unique identifiers). An attacker can manipulate a series of subscription UIDs to trigger mass unsubscription of all newsletter subscribers. This means that by crafting specific requests with modified UIDs, an attacker can forcibly unsubscribe every subscriber from the newsletter without authorization. The vulnerability is classified under CWE-285, which relates to improper authorization, indicating that the extension fails to properly verify whether the user initiating the deleteAction has the rights to perform mass unsubscriptions. There is no indication that authentication or user interaction is required for exploitation, suggesting that the attack could be performed remotely if the endpoint is accessible. No known exploits have been reported in the wild, and no patches or vendor advisories are linked in the provided data. The impact primarily affects the availability and integrity of subscriber data, as legitimate subscribers are removed without consent, potentially disrupting communication channels and damaging organizational reputation. Since the vulnerability targets a specific TYPO3 extension, the scope is limited to websites using this extension in the affected versions. TYPO3 is widely used in Europe, especially in Germany and neighboring countries, which increases the relevance of this vulnerability for European organizations relying on TYPO3 for their digital presence.

For European organizations, the impact of CVE-2022-47409 can be significant in terms of operational disruption and reputational damage. Organizations that rely on newsletters for customer engagement, marketing, or internal communications may experience a sudden loss of subscriber data, leading to communication breakdowns and potential loss of business opportunities. The forced mass unsubscription can also erode trust among subscribers, who may perceive the organization as unable to protect their subscription preferences. This could lead to increased unsubscribe rates even after remediation. Additionally, organizations in sectors with strict data protection regulations, such as GDPR in the EU, might face compliance challenges if subscriber data integrity is compromised, although this vulnerability does not appear to expose personal data directly. The disruption to communication channels can be particularly damaging for public sector entities, educational institutions, and media organizations that use TYPO3 extensively. Furthermore, the ease of exploitation without authentication raises concerns about automated attacks or abuse by malicious actors aiming to sabotage communication efforts or cause reputational harm. While no known exploits are reported, the vulnerability's presence in multiple versions of a widely used extension increases the risk of opportunistic attacks.

1. Immediate Upgrade: Organizations should promptly upgrade the fp_newsletter extension to the latest patched version (at least 1.1.1, 1.2.0, 2.1.2, 2.4.1, or 3.2.6 and above) as soon as vendor patches become available. 2. Access Controls: Restrict access to the newsletter management endpoints by implementing strong access controls, such as IP whitelisting, VPN access, or web application firewall (WAF) rules to block unauthorized requests to deleteAction operations. 3. Authentication Enforcement: Ensure that all newsletter management operations require proper authentication and authorization checks, ideally integrating with TYPO3’s user permission system to prevent unauthorized mass unsubscriptions. 4. Monitoring and Logging: Enable detailed logging of subscription management actions and monitor for unusual patterns, such as bulk unsubscribe requests or repeated failed authorization attempts, to detect potential exploitation attempts early. 5. Rate Limiting: Implement rate limiting on subscription management endpoints to reduce the risk of automated mass unsubscribe attacks. 6. Backup and Recovery: Regularly back up subscriber lists and implement quick recovery procedures to restore subscriber data if mass unsubscriptions occur. 7. Incident Response Preparedness: Prepare communication plans to inform subscribers promptly in case of disruption and reassure them about corrective measures. 8. Security Testing: Conduct regular security assessments and penetration testing on TYPO3 installations and extensions to identify and remediate similar authorization issues proactively.