CVE-2022-25326 is a vulnerability classified under CWE-400 (Uncontrolled Resource Consumption) affecting the fscrypt tool developed by Google LLC. Fscrypt is a utility used to manage encryption policies on filesystems, primarily ext4, f2fs, and ubifs, enabling filesystem-level encryption on Linux systems. The vulnerability exists in versions of fscrypt up to and including v0.3.2, where the tool creates a world-writable directory by default during the setup of a filesystem encryption policy. This misconfiguration allows any unprivileged user on the system to write arbitrary data into this directory. Consequently, an attacker can exhaust the filesystem's available space by filling this directory with data, leading to denial of service conditions due to resource exhaustion. The vulnerability does not require elevated privileges or authentication beyond local user access, and no user interaction is necessary beyond executing commands or scripts that write data to the directory. The issue was addressed in fscrypt version 0.3.3 and later, where directory permissions were corrected to prevent world-writable access. Additionally, it is recommended to audit and adjust permissions on existing fscrypt metadata directories to mitigate the risk on systems still running vulnerable versions. There are no known exploits in the wild targeting this vulnerability, and no CVSS score has been assigned. The vulnerability primarily impacts Linux systems using fscrypt for filesystem encryption management, which are common in enterprise environments that prioritize data security and encryption at rest.

For European organizations, the impact of CVE-2022-25326 can be significant in environments where fscrypt is deployed to manage encrypted filesystems. The uncontrolled resource consumption vulnerability can lead to denial of service by exhausting disk space, potentially disrupting critical applications and services relying on encrypted storage. This could affect data availability and operational continuity, especially in sectors with stringent data protection requirements such as finance, healthcare, and government. Although the vulnerability does not directly compromise confidentiality or integrity, the resulting denial of service could indirectly impact business operations and compliance with data protection regulations like GDPR. Organizations with multi-user Linux systems, particularly those that allow unprivileged local user access, are at higher risk. The vulnerability could be exploited by malicious insiders or compromised local accounts to degrade system performance or cause outages. Given the default world-writable directory creation, even non-privileged users can trigger the resource exhaustion, increasing the attack surface. The absence of known exploits reduces immediate risk but does not eliminate the potential for future exploitation, especially as awareness of the vulnerability spreads.

To mitigate CVE-2022-25326, European organizations should: 1) Upgrade fscrypt to version 0.3.3 or later, where the directory permission issue is resolved. 2) Audit existing fscrypt metadata directories on all systems to identify any world-writable directories and immediately adjust permissions to restrict write access to authorized users only (e.g., root or the fscrypt managing user). 3) Implement monitoring on filesystem usage, particularly on encrypted filesystem metadata directories, to detect unusual or rapid consumption of disk space that could indicate exploitation attempts. 4) Limit local user access rights and enforce the principle of least privilege to reduce the number of users who can write to sensitive filesystem areas. 5) Incorporate fscrypt configuration and permission checks into regular security audits and compliance assessments. 6) Educate system administrators about this vulnerability and the importance of secure filesystem permission settings. 7) Where possible, isolate critical encrypted filesystems from general user write access to minimize risk. These steps go beyond generic advice by focusing on permission auditing, monitoring, and access control specific to the fscrypt metadata directories.