Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!uwm.edu!ux1.cso.uiuc.edu!mp.cs.niu.edu!rickert From: rickert@mp.cs.niu.edu (Neil Rickert) Newsgroups: comp.unix.wizards Subject: Re: DON'T USE 'FU/usr/lib/uucp/L.sys' in sendmail.cf Message-ID: <1991Apr3.142143.6478@mp.cs.niu.edu> Date: 3 Apr 91 14:21:43 GMT References: <3449@unisoft.UUCP> <1991Mar27.204357.17066@mp.cs.niu.edu> <3250@charon.cwi.nl> Organization: Northern Illinois University Lines: 28 In article <3250@charon.cwi.nl> piet@cwi.nl (Piet Beertema) writes: > > As stated earlier, it is potentially dangerous to use 'F' lines in > sendmail.cf to read sensitive files, such as /usr/lib/uucp/L.sys > (or whatever your UUCP systems file is called). >Depends. If you're running 5.64 or older *and* if >you do *not* have >#define SCANF 1 >in your conf.h, then indeed sensitive information >can end up in your frozen config file. In my original posting, I warned that making the freeze file mode 600 is not a guaranteed protection, since a core dump will also contain a copy of the sensitive information. A number of people have suggested that a core dump is impossible, since sendmail runs with effective uid of root, so cannot be sent a core dumping signal. This however, is erroneous. Normally sendmail begins with an effective uid of root, but it can change its uid during processing. In particular there are many choices of command line parameters which will cause sendmail to relinquish its suid privileges after it has read its configuration. -- =*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*= Neil W. Rickert, Computer Science Northern Illinois Univ. DeKalb, IL 60115 +1-815-753-6940