CVE-2017-18261 Explained : Impact and Mitigation

In the Linux kernel prior to version 4.13, a vulnerability exists in the arch_timer_reg_read_stable macro that can be exploited by local users to trigger a denial of service attack through infinite recursion.

Understanding CVE-2017-18261

This CVE entry highlights a specific vulnerability in the Linux kernel that could lead to a denial of service attack.

What is CVE-2017-18261?

The arch_timer_reg_read_stable macro in the Linux kernel before version 4.13 allows local users to cause a denial of service by writing to a file under /sys/kernel/debug in certain circumstances.

The Impact of CVE-2017-18261

The vulnerability can be exploited by users with local access to trigger a denial of service attack through infinite recursion. This can be achieved by writing to a specific file located under the /sys/kernel/debug directory in certain conditions.

Technical Details of CVE-2017-18261

This section provides more technical insights into the vulnerability.

Vulnerability Description

The arch_timer_reg_read_stable macro in the Linux kernel before version 4.13 allows local users to cause a denial of service (infinite recursion) by writing to a file under /sys/kernel/debug in certain circumstances.

Affected Systems and Versions

Product: n/a
Vendor: n/a
Versions: n/a

Exploitation Mechanism

The exploitation of this vulnerability involves utilizing debugfs, ftrace, PREEMPT_TRACER, and FUNCTION_GRAPH_TRACER in a specific scenario.

Mitigation and Prevention

Protecting systems from this vulnerability requires immediate actions and long-term security practices.

Immediate Steps to Take

Monitor and restrict access to the /sys/kernel/debug directory.
Regularly update the Linux kernel to versions beyond 4.13 to mitigate the vulnerability.

Long-Term Security Practices

Implement proper file system permissions to prevent unauthorized writes to critical files.
Conduct regular security audits to identify and address potential vulnerabilities.

Patching and Updates

Apply patches provided by the Linux kernel community to address this vulnerability.