CVE-2023-30571 Explained : Impact and Mitigation

Libarchive through 3.6.2 can cause directories to have world-writable permissions due to a race condition, allowing low-privileged users to delete and rename files.

Understanding CVE-2023-30571

This CVE affects libarchive through version 3.6.2, potentially leading to a security vulnerability that allows local users to manipulate files in directories with improper permissions.

What is CVE-2023-30571?

CVE-2023-30571 describes a race condition in libarchive through version 3.6.2 that can result in directories having world-writable permissions, enabling unauthorized users to modify files within these directories.

The Impact of CVE-2023-30571

The impact of CVE-2023-30571 is that low-privileged local users can exploit the vulnerability to delete and rename files due to directories having improper permissions, leading to a potential security risk.

Technical Details of CVE-2023-30571

This section provides detailed technical insights into the vulnerability, affected systems and versions, as well as the exploitation mechanism.

Vulnerability Description

The umask() call inside archive_write_disk_posix.c changes the umask of the process temporarily, potentially setting it to 0 due to a race condition. This could result in implicit directory creation with insecure permissions.

Affected Systems and Versions

The vulnerability impacts all systems using libarchive through version 3.6.2, exposing them to the risk of world-writable directories under specific conditions.

Exploitation Mechanism

A race condition with another thread during the umask() call can lead to a permanent umask setting of 0. This can allow low-privileged local users to manipulate files within affected directories.

Mitigation and Prevention

To address CVE-2023-30571, immediate steps should be taken to secure affected systems and implement long-term security practices.

Immediate Steps to Take

Administrators should monitor directories for unauthorized changes, restrict access to sensitive files, and apply patches or updates provided by the vendor.

Long-Term Security Practices

Implementing the principle of least privilege, conducting regular security audits, and educating users on file permissions best practices can help prevent similar vulnerabilities.

Patching and Updates

Stay informed about security patches and updates released by libarchive to address CVE-2023-30571 and follow best practices for system maintenance and security hardening.