The vulnerability identified as CVE-2025-67809 affects Zimbra Collaboration Suite (ZCS) versions 10.0 and 10.1, specifically within the Flickr Zimlet component. This Zimlet integrates Flickr services into the collaboration platform and, critically, contained a hardcoded Flickr API key and secret within its publicly accessible code. Because these credentials are embedded directly in the client-side code, any attacker can retrieve them without authentication. With these credentials, an attacker can impersonate the legitimate Zimbra Flickr application and initiate OAuth authorization flows with Flickr. If a user is tricked into approving such an OAuth request, the attacker gains access to the user's Flickr account data, potentially including private photos and personal information. The vulnerability does not directly compromise Zimbra's core systems but leverages the third-party Flickr integration to access user data. The hardcoded credentials have been removed in subsequent updates, and the Flickr API key has been revoked to prevent misuse. No evidence of active exploitation has been reported, but the risk remains for organizations running the affected versions without patches or mitigations.

For European organizations, this vulnerability primarily threatens the confidentiality of user data linked to Flickr accounts accessed via Zimbra Collaboration. While the core Zimbra platform remains uncompromised, the exposure of Flickr credentials could lead to unauthorized access to sensitive personal or corporate images and metadata stored on Flickr. This could result in privacy violations, reputational damage, and potential compliance issues under GDPR if personal data is exposed. Organizations using Zimbra Collaboration with the Flickr Zimlet integrated may face targeted phishing or social engineering attacks to trick users into approving malicious OAuth requests. The impact is limited to users who interact with the Flickr Zimlet and approve OAuth flows, but given the widespread use of Zimbra in European enterprises and public sector entities, the potential scope is significant. The absence of known exploits reduces immediate risk, but the vulnerability's nature means it could be exploited opportunistically or in targeted campaigns.

European organizations should immediately verify if they are running Zimbra Collaboration versions 10.0 or 10.1 with the Flickr Zimlet enabled. If so, they should upgrade to a patched version where the hardcoded credentials have been removed or disable the Flickr Zimlet entirely if the integration is not essential. Additionally, organizations should educate users about the risks of approving OAuth requests from unknown or suspicious sources, emphasizing vigilance against social engineering. Network monitoring for unusual OAuth authorization flows related to Flickr can help detect exploitation attempts. Reviewing and revoking any Flickr API keys associated with the organization is recommended to prevent misuse. Implementing strict application whitelisting and restricting third-party integrations within Zimbra can further reduce attack surfaces. Finally, organizations should audit user accounts for unauthorized access to Flickr data and enforce multi-factor authentication on Flickr accounts where possible.