Article View: gnu.utils.bug
Article #749Is ~/.fingerrc a big security hole in GNU finger 1.35?
From: Erez "HWank1" Zadok
Date: Mon, 07 Sep 1992 04:12
Date: Mon, 07 Sep 1992 04:12
44 lines
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2296 bytes
THE SITUATION: Installing GNU finger 1.35 with the SUPPORT_FINGERRC option will include code to execute a user's ~/.fingerrc file, if it exists and it executable. THE PROBLEM: Isn't this a *BIG* security hole? Yes I know, I can simply undefine this macro and avoid the whole problem. Anyway, I tried a few simple things to see if I can break this feature to gain unauthorized access and other privileges. I was (happily) unable to. This is not to say that it is safe to use. Someone else might find a way to break in. My real problem is that in all of the README and doc files, not even once was it mentioned that this might be a security hole. You *know* that will be the first thing people will complain, so why didn't you say something about that? Why didn't you say how this feature works exactly (I have looked at the src.) IMHO you aught to dispell some fears that will arise by mentioning how safe or unsafe is it to use. The supplied documents bluntly avoided that issue. Having said that, I want to thank you for adding this feature. It is better than the fifo hack that was posted a while ago to the net. This is one neat feature I always wished for. MY SETUP: - GNU finger 1.35 - Sun-4's: everything from 4/25 to 4/630. - Compiler used: gcc 2.2.2 - OS version SunOS 4.1.2 - network configuration: class B, subnets, ciscos, "the usual" stuff. Not really relevant to this bug. We nfs-automount many directories. - Patches: none. Erez Zadok. Mobile Computing Laboratory. Columbia University Department of Computer Science. --- A wank's morning starts one machine | Arpa: ezk@cs.columbia.edu clock cycle after midnight. | Usenet: ...!rutgers!columbia!cs!ezk -HebrewWank #1 (US meaning, not UK!) | Bitnet: erzus@cuvmb.BITNET
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arc1-ca.pugleaf.net!sparky!uunet!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!cis.ohio-state.edu!ground.cs.columbia.edu!ezkShow Full Headers
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Path: arc1-ca.pugleaf.net!sparky!uunet!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!cis.ohio-state.edu!ground.cs.columbia.edu!ezk From: ezk@ground.cs.columbia.edu (Erez "HWank1" Zadok) Newsgroups: gnu.utils.bug Subject: Is ~/.fingerrc a big security hole in GNU finger 1.35? Message-ID: <9209070412.AA10907@ground.cs.columbia.edu> Date: 7 Sep 92 04:12:24 GMT Sender: gnulists@ai.mit.edu Distribution: gnu Organization: GNUs Not Usenet Lines: 44 Approved: bug-gnu-utils@prep.ai.mit.edu