Linux Kernel Siemens R3964 Line Discipline Driver Race Condition Vulnerability [CVE-2019-11486]

CVE Number – CVE-2019-11486

A vulnerability in the Siemens R3964 line discipline driver of the Linux Kernel could allow a local attacker to cause a denial of service (DoS) condition on a targeted system.The vulnerability is due to a race condition that exists in the drivers/tty/n_r3964.c source code file of the affected software. An attacker could exploit this vulnerability by opening the serial port of a Siemens R3964 adapter on the targeted system. A successful exploit could result 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 a software update.

Analysis

• To exploit this vulnerability, the attacker must have user-level access to the targeted system. This access requirement may 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 git commit at the following link: Commit c7084edc3f6d67750f50d4183134c4fb5712a5c8

Fixed Software

• Kernel.org has released a software patch at the following link: tty: mark Siemens R3964 line discipline as BROKEN