Bugtraq mailing list archives
RE: Windows Vista Power Management & Local Security Policy
From: Jim Harrison <Jim () isatools org>
Date: Sun, 20 Jul 2008 13:33:19 -0700
It's about reality & priorities. What we're both saying is: 1. it's a bug and should be fixed in accordance with its impact on real (not imagined) functionality & security 2. unless this provides some exploit that doesn't start with "if I can install software on the host", it's not more than "a bug in a security mechanism" If someone can demonstrate an actual vulnerability or exploit on the basis of this bug _alone_, then they may have something to make noise about. There are enough real bugs and security vulns in software to deal with. Not every security issue spells doom and damnation or warrants immediate corrective response from the vendor. Jim -----Original Message----- From: Abe Getchell [mailto:me () abegetchell com] Sent: Sunday, July 20, 2008 12:32 PM To: 'Thor (Hammer of God)'; Jim Harrison; 'Johan Beisser' Cc: bugtraq () securityfocus com Subject: RE: Windows Vista Power Management & Local Security Policy So, you guys don't think it's an issue that power management in Vista (apparently) has a pass to bypass local security policy? -- Abe Getchell me () abegetchell com https://abegetchell.com/
-----Original Message----- From: Thor (Hammer of God) [mailto:thor () hammerofgod com] Sent: Saturday, July 19, 2008 6:20 PM To: me () abegetchell com; Jim Harrison; bugtraq () securityfocus com Subject: RE: Windows Vista Power Management & Local Security Policy If Jim is going to get Nancy to run a program, and that's "not all that hard," then why not just have that program do what you want in the first place rather than worrying about the power switch nonsense? This is the one million and fourth time: "If your 'vulnerability' begins with 'if I can get the user to run code' then whatever comes after the 'then' doesn't matter. Period." t-----Original Message----- From: Abe Getchell [mailto:me () abegetchell com] Sent: Saturday, July 19, 2008 12:33 AM To: 'Jim Harrison'; bugtraq () securityfocus com Subject: RE: Windows Vista Power Management & Local Security Policy As stated in my original e-mail to the list, I definitely don't think that this is a security vulnerability in a traditional sense. I completely agree with you. Think about it this way... When you press the power buttononthe machine and it performs a graceful shutdown, stuff happens inside of the operating system. That stuff happens at an elevated privilege level.Ifthere were some way to hook into the stuff that happens, you (as an unauthenticated user), could do bad things (besides simply shutting down the system) using that hook simply by pressing the power button at the logon screen. For example, if Jim wants to know what Nancy is working on,hecould write a program which e-mails him the contents of her "My Documents" folder that is triggered by a hook into that process. All Jim needs to do is get Nancy to run that program on her system (not hard) and walk by her office when she's not there and hit the power button (also not hard). Sowhatcan _I_ do with this bug? Not much, I'm not that great of a programmer... but I think someone out there could do some nasty stuff. -- Abe Getchell me () abegetchell com https://abegetchell.com/-----Original Message----- From: Jim Harrison [mailto:Jim () isatools org] Sent: Saturday, July 19, 2008 1:36 AM To: 'me () abegetchell com'; bugtraq () securityfocus com Subject: RE: Windows Vista Power Management & Local Security Policy Abe, Other than a denial-of-service from the console (is the powerswitchnow a security vuln, too?), what can you do with this bug? It's absolutely, unquestionably a "bug"; the user should see behavior as dictated by logic and described in the documentation, but a"securityvulnerability"? I think that's stretching things juuuuuust a bit. Jim -----Original Message----- From: Abe Getchell [mailto:me () abegetchell com] Sent: Thursday, July 17, 2008 7:39 PM To: bugtraq () securityfocus com Subject: Windows Vista Power Management & Local Security Policy When the security option "Shutdown: Allow system to be shutdownwithouthaving to log on" (in the local security policy) is set to"Disable",and the power management setting "When I press the power button" is setto"Shut Down", it is possible for an unauthenticated user to press thepowerbutton at the Windows logon screen and gracefully shutdown the system. The explanation of this security option, taken from the local security policy, is as follows: "Shutdown: Allow system to be shut down without having to log on This security setting determines whether a computer can be shutdownwithout having to log on to Windows. When this policy is enabled, the Shut Down command is available ontheWindows logon screen. When this policy is disabled, the option to shut down the computerdoesnot appear on the Windows logon screen. In this case, *users must beableto log on to the computer successfully and have the Shut down the systemuserright before they can perform a system shutdown*. Default on workstations: Enabled. Default on servers: Disabled." Note the text between the asterisks. While this bug isn'tnecessarilyasoftware flaw allowing for an intrusion into the system in a traditional sense, it does set a bad precedence in that power management has afreepass to bypass local security policy and perform actions expresslyagainstthe defined policy. It appears that the only impact the use of this security option actually has is enabling or disabling the display of the"powerbutton" on the Windows logon screen (locally only - this settinghasnoaffect on remote desktop connections - the "power button" is not displayed in either case), not actually preventing anyone from (gracefully) shutting down the system without logging in. I reported this to the MSRC on 6/25/2008 and their stance was thatthiswasn't a security vulnerability, but was likely a bug, and waspasseddirectly to the product team to investigate through their normalbugtriage process. After some back and forth, there was silence, and I letthemknow I was going to release this information to the community. This was tested on Windows Vista SP1 (32-bit). -- Abe Getchell me () abegetchell com https://abegetchell.com/
Current thread:
- Windows Vista Power Management & Local Security Policy Abe Getchell (Jul 18)
- RE: Windows Vista Power Management & Local Security Policy Jim Harrison (Jul 19)
- RE: Windows Vista Power Management & Local Security Policy Abe Getchell (Jul 19)
- RE: Windows Vista Power Management & Local Security Policy Thor (Hammer of God) (Jul 21)
- RE: Windows Vista Power Management & Local Security Policy Abe Getchell (Jul 21)
- RE: Windows Vista Power Management & Local Security Policy Jim Harrison (Jul 21)
- RE: Windows Vista Power Management & Local Security Policy Abe Getchell (Jul 21)
- RE: Windows Vista Power Management & Local Security Policy James C. Slora Jr. (Jul 22)
- RE: Windows Vista Power Management & Local Security Policy Jim Harrison (Jul 22)
- RE: Windows Vista Power Management & Local Security Policy Abe Getchell (Jul 23)
- RE: Windows Vista Power Management & Local Security Policy Abe Getchell (Jul 19)
- RE: Windows Vista Power Management & Local Security Policy Jim Harrison (Jul 19)
- <Possible follow-ups>
- RE: Windows Vista Power Management & Local Security Policy Good Securitypractice (Jul 23)