CVE-2017-8900 : What You Need to Know
Learn about CVE-2017-8900, a vulnerability in LightDM up to version 1.22.0 on Ubuntu 16.10 and 17.x, allowing attackers to bypass AppArmor restrictions and access user home directories.
In Ubuntu 16.10 and 17.x, a vulnerability in LightDM version up to 1.22.0 could allow nearby attackers to bypass AppArmor restrictions, potentially accessing home directories of different users.
Understanding CVE-2017-8900
What is CVE-2017-8900?
LightDM, when used with systemd in Ubuntu 16.10 and 17.x, may permit physically proximate attackers to override intended AppArmor restrictions, leading to unauthorized access to user home directories.
The Impact of CVE-2017-8900
The vulnerability could enable attackers to view sensitive information stored in home directories of various users by initiating a guest session.
Technical Details of CVE-2017-8900
Vulnerability Description
LightDM up to version 1.22.0 in Ubuntu 16.10 and 17.x allows attackers to bypass AppArmor restrictions, potentially compromising user data.
Affected Systems and Versions
- LightDM version up to 1.22.0
- Ubuntu 16.10 and 17.x
Exploitation Mechanism
Attackers can exploit the vulnerability by establishing a guest session, bypassing AppArmor restrictions, and accessing home directories of arbitrary users.
Mitigation and Prevention
Immediate Steps to Take
- Update LightDM to a patched version
- Monitor system logs for any suspicious activity
- Restrict physical access to systems
Long-Term Security Practices
- Implement strong access controls and user permissions
- Regularly review and update security configurations
Patching and Updates
Apply security patches provided by Ubuntu to address the vulnerability.