Redhat 7 insecure umask

From: Drew Jones (drewjat_private)
Date: Fri Apr 20 2001 - 13:41:05 PDT

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    Problem:
      Users of Redhat 7 may have their umask set insecurely while acting as root.
    
    Severity:
      Medium/Low
    
    Description:
      The Redhat useradd script creates a group for the new user with the same
    name as the username by default.  When the user logs in, any shell that uses
    /etc/profile will set the umask to 002 if the user's username and groupname
    match and their uid is greater than 14.  If the user then issues su to become
    root without specifying the -l option the root account inherits the umask of
    002.  As root the user may then create files with somewhat insecure permissions.
    Redhat seemed to understand that system users should have a umask of 022,
    because /etc/profile will set the umask that way for users loging in with a
    uid less than 14, but they forgot about su.
    
    The offending lines in /etc/profile:
    ...
    if [ `id -gn` = `id -un` -a `id -u` -gt 14 ]; then
            umask 002
    else
            umask 022
    fi
    ...
    
    The fix:
      Get rid of the if-statement in /etc/profile and replace it with
    'umask 022' (no quotes).
    
    
    Andrew Jones
    -------------
    Computer Science and Physics student at the University of Northern Iowa
    



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