[NT] RunAs Allows Bypassing User GPO in Windows XP/2003

2005-12-28T00:00:00
ID SECURITYVULNS:DOC:10837
Type securityvulns
Reporter Securityvulns
Modified 2005-12-28T00:00:00

Description

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RunAs Allows Bypassing User GPO in Windows XP/2003

SUMMARY

Microsoft Windows allows users to define
<http://www.microsoft.com/resources/documentation/Windows/XP/all/reskit/en-us/prda_dcm_qnos.asp> GPOs (Group Policy Objects) in a domain environment. GPO is used by many network administrators to restrict the permissions of users.

By using the RunAs functionality of Windows it is possible to bypass user GPO settings completely.

DETAILS

By using the run as or the runas /noprofile commands it is possible to bypass user GPO settings completely.

Example: 1. Set up a domain with strict security settings. e.g. Software restrictions policies, hide local drives, remove "run", disable cmd.exe and so on.

  1. Log on to an XP computer in that domain - make a link to cmd.exe - select "run as" on that link.
  2. Logon with another user in the same domain - with the same restrictions
  3. you'll see that the GPO's will not be loaded for that user.

Vendor Response: Microsoft was contacted by the author, and replied that user restrictions under GPO are not to be used as a security measure, but instead, it is used to prevent users from damaging their environment.

Note that GPO restrictions are widely used as a security enhancement, and several Microsoft documents recommend this step in security policies. For example in:
<http://www.microsoft.com/smallbusiness/support/articles/sec_winxp_pro_server_env.mspx#EJAA> http://www.microsoft.com/smallbusiness/support/articles/sec_winxp_pro_server_env.mspx#EJAA

ADDITIONAL INFORMATION

The information has been provided by <mailto:espen@espen.mine.nu> Espen.

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