CVE-2019-7307 : Vulnerability Insights and Analysis

CVE-2019-7307, assigned by Canonical, relates to a TOCTTOU vulnerability in Apport when reading the users' ~/.apport-ignore.xml file.

Understanding CVE-2019-7307

This CVE involves a local attacker exploiting a TOCTTOU issue in Apport, potentially leading to unauthorized access to system files.

What is CVE-2019-7307?

Versions of Apport before specific releases had a vulnerability allowing a local attacker to manipulate the ~/.apport-ignore.xml file, gaining unauthorized access to arbitrary files on the system.

The Impact of CVE-2019-7307

The vulnerability could enable an attacker to access sensitive system files by exploiting a TOCTTOU issue in Apport.

Technical Details of CVE-2019-7307

This section provides detailed technical information about the vulnerability.

Vulnerability Description

The vulnerability in Apport allowed a local attacker to replace the ~/.apport-ignore.xml file with a symlink to another file, leading to unauthorized access to system files.

Affected Systems and Versions

Vendor: Ubuntu
Product: apport
Affected Versions:
before 2.14.1-0ubuntu3.29+esm1
before 2.20.1-0ubuntu2.19
before 2.20.9-0ubuntu7.7
before 2.20.10-0ubuntu27.1
before 2.20.11-0ubuntu5

Exploitation Mechanism

The attacker could manipulate the ~/.apport-ignore.xml file to include a symlink to another file, tricking Apport into including the substituted file's contents in the crash report.

Mitigation and Prevention

Steps to address and prevent the CVE-2019-7307 vulnerability.

Immediate Steps to Take

Update Apport to versions that address the vulnerability.
Monitor system logs for any suspicious activity related to file modifications.

Long-Term Security Practices

Implement least privilege access controls to limit file system access.
Regularly review and update security configurations to prevent similar vulnerabilities.

Patching and Updates

Apply patches provided by the vendor to fix the vulnerability and enhance system security.