Bug 610802 (CVE-2017-2616)

Summary:	[TRACKER] su: user can send SIGKILL with root privileges to other processes (CVE-2017-2616)
Product:	Gentoo Security	Reporter:	Thomas Deutschmann (RETIRED) <whissi>
Component:	Vulnerabilities	Assignee:	Gentoo Security <security>
Status:	RESOLVED FIXED
Severity:	normal	Keywords:	Tracker
Priority:	Normal
Version:	unspecified
Hardware:	All
OS:	Linux
Whiteboard:
Package list:		Runtime testing required:	---
Bug Depends on:	610664, 610804
Bug Blocks:

Description Thomas Deutschmann (RETIRED) gentoo-dev

2017-02-24 12:24:03 UTC

If su is compiled with PAM support, it is possible for any local user to send SIGKILL to other processes with root privileges. To exploit this, the user must be able to perform su with a successful login. This does NOT have to be the root user, even using su with the same id is enough, e.g. "su $(whoami)". SIGKILL can only be sent to processes which were executed after the su process. It is not possible to send SIGKILL to processes which were already running.