CVE-2022-24885 is a security vulnerability identified in the Nextcloud Android application, a client app for the Nextcloud self-hosted productivity platform. The vulnerability is classified under CWE-287, which pertains to improper authentication mechanisms. Specifically, in versions of the Nextcloud Android app prior to 3.19.1, an attacker can bypass the app's lock screen by repeatedly reopening the app. This flaw effectively undermines the authentication lock intended to protect user data within the app on Android devices. The vulnerability does not require known exploits in the wild, and no workarounds have been documented, but it was addressed and fixed in version 3.19.1 of the app. The issue arises because the app fails to properly enforce the lock state upon repeated app launches, allowing unauthorized access to the app's contents without proper authentication. Since Nextcloud is widely used for file sharing, collaboration, and productivity, unauthorized access to the app could expose sensitive files and information stored or synchronized through the platform. The vulnerability affects only the Android client app and not the server-side Nextcloud platform itself. The flaw is limited to the lock bypass on the client device and does not indicate remote code execution or server compromise. However, the impact on confidentiality is significant as it allows local attackers or anyone with physical access to the device to circumvent app-level authentication controls.

For European organizations, the impact of CVE-2022-24885 can be considerable, especially for those relying on Nextcloud for secure collaboration and data sharing. The vulnerability allows unauthorized access to the Nextcloud app on Android devices, potentially exposing sensitive corporate documents, personal data, and other confidential information. This could lead to data leakage, violation of data protection regulations such as GDPR, and loss of trust in the organization's security posture. Since the vulnerability requires physical or local access to the device, the risk is higher in environments where devices are shared, lost, or stolen. Organizations with mobile workforces or BYOD policies are particularly vulnerable. The flaw does not enable remote exploitation, so the threat is limited to attackers with direct access to the device. However, given the widespread use of Nextcloud in Europe, especially among SMEs and public sector entities valuing self-hosted solutions, the potential for data exposure is non-trivial. The vulnerability could also be exploited in targeted attacks where adversaries gain temporary physical access to devices. Overall, the impact is primarily on confidentiality and user data privacy, with limited effect on integrity or availability of the Nextcloud service itself.

To mitigate this vulnerability, European organizations should prioritize updating all Nextcloud Android client applications to version 3.19.1 or later, where the issue has been fixed. Since no workarounds exist, patching is the only effective remediation. Organizations should implement mobile device management (MDM) solutions to enforce app updates and monitor device compliance. Additionally, enforcing strong device-level security controls such as full-disk encryption, strong lock screens, and biometric authentication can reduce the risk of unauthorized physical access. Educating users about the importance of promptly updating apps and securing their devices is critical. For environments with high security requirements, consider restricting the use of Nextcloud Android clients on unmanaged or personal devices until they are updated. Organizations should also review their data access policies and consider additional app-level encryption or containerization solutions to protect sensitive data on mobile devices. Regular audits of mobile device security posture and incident response plans for lost or stolen devices will further reduce risk.