#VU9515 NULL pointer dereference in Linux kernel - CVE-2017-15102
Published: December 1, 2017 / Updated: December 1, 2017
Vulnerability identifier: #VU9515
Vulnerability risk: Low
CVSSv4.0: CVSS:4.0/AV:P/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2017-15102
CWE-ID: CWE-476
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerable software:
Linux kernel
Linux kernel
Software vendor:
Linux Foundation
Linux Foundation
Description
The vulnerability allows a local user to escalate privileges.
The vulnerability exists due to a race condition and a NULL pointer dereference within tower_probe() function in drivers/usb/misc/legousbtower.c in Linux kernel before 4.8.1. A local user with physical access to the computer and ability to insert USB flash drive can execute arbitrary code with escalated privileges. The USB device would have to delay the control message in tower_probe and accept the control urb in tower_open whilst guest code initiated a write to the device file as tower_delete is called from the error in tower_probe.
According to vendor this security issue exists since 2003.
The vulnerability exists due to a race condition and a NULL pointer dereference within tower_probe() function in drivers/usb/misc/legousbtower.c in Linux kernel before 4.8.1. A local user with physical access to the computer and ability to insert USB flash drive can execute arbitrary code with escalated privileges. The USB device would have to delay the control message in tower_probe and accept the control urb in tower_open whilst guest code initiated a write to the device file as tower_delete is called from the error in tower_probe.
According to vendor this security issue exists since 2003.
Remediation
Install a patch from vendor's repository:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=2fae9e5a7babada041e2e1...
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=2fae9e5a7babada041e2e1...