The DebuggerFunction::InitAgentHost function in browser/extensions/api/debugger/debugger_api.cc in Google Chrome before 41.0.2272.76 does not properly restrict what URLs are available as debugger targets, which allows remote attackers to bypass intended access restrictions via a crafted extension.
https://security.gentoo.org/glsa/201503-12
https://codereview.chromium.org/910053002
https://code.google.com/p/chromium/issues/detail?id=456841
http://www.securityfocus.com/bid/72901
http://rhn.redhat.com/errata/RHSA-2015-0627.html
http://googlechromereleases.blogspot.com/2015/03/stable-channel-update.html