Article View: comp.bugs.sys5
Article #734Re: A security hole
From: terry
Date: Tue, 15 Mar 1988 02:57
Date: Tue, 15 Mar 1988 02:57
45 lines
2921 bytes
2921 bytes
In article <478@minya.UUCP>, jc@minya.UUCP (John Chambers) writes:
} In article <722@rivm05.UUCP>, ccement@rivm.UUCP (Martien F v Steenbergen) writes:
} In article <181@wsccs.UUCP>, I write:
} >
} > Do NOT write a setuid program that uses getcwd(). The getcwd() call
} > does a popen() of the "pwd" shell command and does not check it's path.
}
} Also, I'm sure that I'm far from the only one who is getting tired of seeing
} dire warnings like:
} The 'cc' command contains a MAJOR security hole; you should delete it
} from your system as fast as possible. I can't tell you what the hole
} is, because it would allow any hacker to break into any Unix system in
} the world. Believe me; I know what I'm talking about.
} It's easy enough to make up warnings like these, but many of them turn out
} on investigation to be full of bull; some are in fact fraudulent attempts
} to discredit someone else's useful software.
Read the source code. I was simply pointing out something you should
be aware of. The fix, if you haven't figured it out for yourself yet, is to
simply force the path for pwd. I was simply suggesting that AT&T fix it.
} Anyhow, what can one do with getcwd() or popen() within a setuid program
} (root or otherwise) that isn't a consequence of the search path?
Nothing. That's not the point. How do you specify the PATH env
variable from within your C program? Inquiring minds want to know...
the who point, I thought, of this bugs forum, was to bring bugs to the
attention of the people in charge of removing them.
} If there
} is a real security hole here, I'd be very interested in reading about it.
Well... how do _you_ do a mknod under sys5? Is it a suid root program
on _your_ system, like everone elses, or do you always log in as root? Do you
determine path via osmosis, or some method unbeknownst to us? If not, it's
a problem.
When all else fails, consult the source code.
| Terry Lambert UUCP: ...!{ decvax, ihnp4 }... |
| @ Century Software or : ...utah-cs!uplherc!sp7040!obie!wsccs!terry |
| SLC, Utah |
| These opinions are not my companies, but if you find them |
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| 'There are monkey boys in the facility. Do not be alarmed; you are secure' |
Technical Details
Message-ID:
<319@wsccs.UUCP>Path:
arc1-ca.pugleaf.net!utzoo!mnetor!uunet!lll-winken!lll-lcc!ames!nrl-cmf!mailrus!tut.cis.ohio-state.edu!ut-sally!utah-cs!utah-gr!uplherc!sp7040!wsccs!terryReferences:
<181@wsccs.UUCP> <722@rivm05.UUCP> <478@minya.UUCP>Show Full Headers
Complete Article Headers
Path: arc1-ca.pugleaf.net!utzoo!mnetor!uunet!lll-winken!lll-lcc!ames!nrl-cmf!mailrus!tut.cis.ohio-state.edu!ut-sally!utah-cs!utah-gr!uplherc!sp7040!wsccs!terry From: terry@wsccs.UUCP (terry) Newsgroups: comp.bugs.sys5 Subject: Re: A security hole Message-ID: <319@wsccs.UUCP> Date: 15 Mar 88 02:57:04 GMT References: <181@wsccs.UUCP> <722@rivm05.UUCP> <478@minya.UUCP> Lines: 44 Summary: Use the source, Luke