Text File

Aucbvax.3107 fa.unix-wizards utzoo!decvax!ucbvax!unix-wizards Sat Sep 12 01:15:02 1981 Problems with turning off setuid >From MathStat.jmrubin@Berkeley Sat Sep 12 00:52:45 1981 From csvax:unix-wizards Fri Sep 11 21:23:14 1981 Subject: Problems with turning off setuid Newsgroups: fa.unix-wizards >From decvax!duke!unc!smb@Berkeley Fri Sep 11 21:04:18 1981 In-real-life: Steven M. Bellovin Location: University of North Carolina at Chapel Hill

Although I feel that Berkeley's practice is indeed a reasonable protection scheme, it can cause problems. For example, I sometimes create setuid programs that have group-write permission. To test a new version, I can just copy the file into it, without having to 'su' each time. Assuming that /etc/group is secure (or no less secure than /etc/passwd, at any rate), there is no security risk.

I don't think that group security is as strong as individual security. On at least some systems, the empty core-dump from a setgid program can be made into a setgid program to fork a shell. (or do anything else) Thus, if you have this system, you may give someone the total permissions which the owner of the setuid program has.

By the way, we seem to be getting all messages from Steven Bellovin in duplicate or triplicate. Anyone know why? Joel Rubin

----------------------------------------------------------------- gopher://quux.org/ conversion by John Goerzen <jgoerzen@complete.org> of http://communication.ucsd.edu/A-News/

This Usenet Oldnews Archive article may be copied and distributed freely, provided:

1. There is no money collected for the text(s) of the articles.

2. The following notice remains appended to each copy:

The Usenet Oldnews Archive: Compilation Copyright (C) 1981, 1996 Bruce Jones, Henry Spencer, David Wiseman.