misc.cpp in KPopup 0.9.1 trusts the PATH variable when executing killall, which allows local users to elevate their privileges by modifying the PATH variable to reference a malicious killall program.
https://exchange.xforce.ibmcloud.com/vulnerabilities/13540
https://euvd.enisa.europa.eu/vulnerability/EUVD-2003-1157
http://www.securityfocus.com/bid/8915