CVE-2017-16939 : Exploit Details and Defense Strategies
Learn about CVE-2017-16939, a Linux kernel vulnerability that allows local users to gain privileges or cause denial of service. Find mitigation steps and update information here.
The implementation of the XFRM dump policy in net/xfrm/xfrm_user.c within the Linux kernel prior to version 4.13.11 may enable local users to elevate their privileges or create a denial of service (use-after-free) by using a malicious SO_RCVBUF setsockopt system call in combination with XFRM_MSG_GETPOLICY Netlink messages.
Understanding CVE-2017-16939
This CVE involves a vulnerability in the Linux kernel that could allow local users to gain elevated privileges or cause a denial of service.
What is CVE-2017-16939?
The XFRM dump policy implementation in net/xfrm/xfrm_user.c in the Linux kernel before version 4.13.11 allows local users to gain privileges or cause a denial of service (use-after-free) via a crafted SO_RCVBUF setsockopt system call in conjunction with XFRM_MSG_GETPOLICY Netlink messages.
The Impact of CVE-2017-16939
- Local users may exploit this vulnerability to elevate their privileges or trigger a denial of service attack.
Technical Details of CVE-2017-16939
This section provides more in-depth technical details about the CVE.
Vulnerability Description
The XFRM dump policy implementation in net/xfrm/xfrm_user.c in the Linux kernel before 4.13.11 allows local users to gain privileges or cause a denial of service (use-after-free) via a crafted SO_RCVBUF setsockopt system call in conjunction with XFRM_MSG_GETPOLICY Netlink messages.
Affected Systems and Versions
- Affected systems are those running Linux kernel versions prior to 4.13.11.
Exploitation Mechanism
- Local users can exploit this vulnerability by using a malicious SO_RCVBUF setsockopt system call along with XFRM_MSG_GETPOLICY Netlink messages.
Mitigation and Prevention
Protecting systems from CVE-2017-16939 is crucial to maintaining security.
Immediate Steps to Take
- Update the Linux kernel to version 4.13.11 or newer to mitigate the vulnerability.
- Monitor system logs for any suspicious activities that could indicate an exploit attempt.
Long-Term Security Practices
- Implement the principle of least privilege to restrict user access and minimize the impact of potential attacks.
- Regularly review and update security configurations to address any new vulnerabilities.
Patching and Updates
- Stay informed about security advisories and patches released by Linux distributions and vendors to promptly apply necessary updates.