Article View: comp.bugs.2bsd
Article #253Re: Cuserid() is a security hole
From: Rob Bernardo
Date: Thu, 08 Jun 1989 00:52
Date: Thu, 08 Jun 1989 00:52
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1640 bytes
In article <1768@auspex.auspex.com> guy@auspex.auspex.com (Guy Harris) writes: +If you consider it a bug to be able to redirect standard input and, as a +result, be able to force "getlogin" give you the wrong information, you +might find it is a bug in many versions of UNIX, *including* Ultrix.... The "problem" is that a programmer might use cuserid() without knowing about this "deception". This might be particularly bad in, say, a mail user agent. MUA's often must run setgid. As a setgid program is has access to *anyone's* incoming mail box, and must judge whether the user would normally be able to access the mailbox s/he has directed the MUA to access. If cuserid() is used to determine the user's id, the MUA may unwittingly grant access to some other person's incoming mailbox. -- Rob Bernardo, Pacific Bell UNIX/C Reusable Code Library Email: ...![backbone]!pacbell!pbhyf!rob OR rob@pbhyf.PacBell.COM Office: (415) 823-2417 Room 4E850O San Ramon Valley Administrative Center Residence: (415) 827-4301 R Bar JB, Concord, California
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arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!sun-barr!cs.utexas.edu!csd4.milw.wisc.edu!bionet!ames!pacbell!pbhyf!robReferences:
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!sun-barr!cs.utexas.edu!csd4.milw.wisc.edu!bionet!ames!pacbell!pbhyf!rob From: rob@PacBell.COM (Rob Bernardo) Newsgroups: comp.bugs.2bsd,comp.bugs.4bsd,comp.bugs.sys5,comp.unix.wizards Subject: Re: Cuserid() is a security hole Message-ID: <5495@pbhyf.PacBell.COM> Date: 8 Jun 89 00:52:41 GMT References: <289@levels.sait.edu.au> <472@imokay.dec.com> <1768@auspex.auspex.com> Reply-To: rob@PacBell.COM (Rob Bernardo) Followup-To: comp.bugs.2bsd Organization: Pacific * Bell, San Ramon, CA Lines: 19