CVE-2018-1091 Explained : Impact and Mitigation
Learn about CVE-2018-1091 affecting Linux kernel versions prior to 4.13.5 and newer. Find out how unprivileged userspace can trigger a denial of service on a POWER host.
CVE-2018-1091 was published on March 27, 2018, by Red Hat. It affects the Linux kernel version prior to 4.13.5 and newer versions. The vulnerability lies in the flush_tmregs_to_thread function in the ptrace.c file, potentially leading to a denial of service on a POWER host.
Understanding CVE-2018-1091
This CVE entry highlights a vulnerability in the Linux kernel that could be exploited by unprivileged userspace to trigger a crash in the guest kernel during a core dump on a POWER host.
What is CVE-2018-1091?
The vulnerability in the Linux kernel version prior to 4.13.5 stems from a missing check for a processor feature and an incorrect use of transactional memory (TM) instructions during the core dump process.
The Impact of CVE-2018-1091
The vulnerability can result in a denial of service when unprivileged userspace attempts a core dump on a POWER host due to the crash triggered in the guest kernel.
Technical Details of CVE-2018-1091
CVE-2018-1091 involves the following technical aspects:
Vulnerability Description
The flush_tmregs_to_thread function in the Linux kernel before version 4.13.5 allows unprivileged userspace to cause a crash in the guest kernel during a core dump on a POWER host.
Affected Systems and Versions
- Product: Linux kernel v4.13 and newer
- Vendor: Not applicable
- Versions: Linux kernel v4.13 and newer
Exploitation Mechanism
The vulnerability is exploited by unprivileged userspace through a missing check for a processor feature and an incorrect utilization of transactional memory (TM) instructions within the core dump process.
Mitigation and Prevention
To address CVE-2018-1091, consider the following steps:
Immediate Steps to Take
- Apply the necessary patches provided by the Linux kernel maintainers.
- Monitor official sources for updates and advisories regarding this vulnerability.
Long-Term Security Practices
- Regularly update the Linux kernel to the latest stable version to mitigate known vulnerabilities.
- Implement proper access controls and permissions to limit the impact of potential exploits.
Patching and Updates
- Stay informed about security updates and patches released by the Linux kernel community.
- Apply patches promptly to ensure the security of your systems.