Linux Kernel dev_get_valid_name Local Denial of Service Vulnerability [CVE-2018-7191]

CVE number – CVE-2018-7191

A vulnerability in the tun subsystem of the Linux Kernel could allow a local attacker to cause a denial of service (DoS) condition on a targeted system.The vulnerability due to a NULL pointer dereference condition in the dev_get_valid_name function of the affected software. An attacker could exploit this vulnerability by accessing the system and making a malicious ioctl(TUNSETIFF) call on the targeted system. A successful exploit could allow the attacker to cause a NULL pointer dereference condition, resulting in a DoS condition on the targeted system.Proof-of-concept (PoC) code that demonstrates an exploit of this vulnerability is publicly available.Kernel.org has confirmed the vulnerability and released software updates.

Analysis

• To exploit this vulnerability, the attacker must have user-level access to the system. This access requirement could reduce the likelihood of a successful exploit.

Safeguards

• Administrators are advised to apply the appropriate updates.Administrators are advised to allow only trusted users to access local systems.Administrators are advised to allow only privileged users to access administration or management systems.Administrators are advised to monitor critical systems.

Vendor Announcements

• Kernel.org has released a Changelog at the following link: ChangeLog 4.13.14

Fixed Software

• Kernel.org has released a software patch at the following link: tun: call dev_get_valid_name() before register_netdevice()