CVE-2019-12779 : Exploit Details and Defense Strategies

libqb before version 1.0.5 has a vulnerability that allows local users to maliciously replace files through a symlink attack. This occurs due to the use of predictable filenames in /dev/shm and /tmp without implementing O_EXCL.

Understanding CVE-2019-12779

This CVE involves a security vulnerability in libqb that can be exploited by local individuals to overwrite arbitrary files on the system.

What is CVE-2019-12779?

CVE-2019-12779 is a vulnerability in libqb versions prior to 1.0.5 that enables local users to perform symlink attacks, leading to unauthorized file replacements.

The Impact of CVE-2019-12779

The vulnerability allows attackers to manipulate files on the system, potentially leading to unauthorized access, data loss, or system compromise.

Technical Details of CVE-2019-12779

This section provides detailed technical information about the CVE.

Vulnerability Description

The vulnerability in libqb before version 1.0.5 allows local users to overwrite arbitrary files through symlink attacks by using predictable filenames in /dev/shm and /tmp without O_EXCL.

Affected Systems and Versions

Affected Version: Prior to 1.0.5
Systems using libqb versions before 1.0.5 are vulnerable to this exploit.

Exploitation Mechanism

Attackers can exploit this vulnerability by creating symbolic links to overwrite files in /dev/shm and /tmp due to the lack of proper file locking mechanisms.

Mitigation and Prevention

Protecting systems from CVE-2019-12779 requires immediate actions and long-term security practices.

Immediate Steps to Take

Update libqb to version 1.0.5 or later to mitigate the vulnerability.
Monitor file changes in critical directories to detect any unauthorized modifications.

Long-Term Security Practices

Implement proper file permission settings to restrict unauthorized access.
Regularly audit and review file system integrity to identify any suspicious activities.

Patching and Updates

Apply security patches provided by libqb to address the vulnerability.
Stay informed about security advisories and updates from the vendor to protect against similar vulnerabilities in the future.