jeff@questar.QUESTAR.MN.ORG (Jeff Holmes) (12/28/88)
I had an odd occurance the other day. I'm not sure how it happened but I got my Minix 1.2 system in such a state that when I type 'su' it made me root without asking for a password. Logging out reset everything to normal. Anyone had this happen before? The setuid bit is set (4755) and su is owned by root. Thanks, Jeff -- Jeff Holmes DOMAIN: jeff@questar.mn.org Questar Data Systems UUCP: amdahl!bungia!questar!jeff
mju@m-net.UUCP (Marc Unangst) (12/30/88)
In article <1971@questar.QUESTAR.MN.ORG> jeff@questar.QUESTAR.MN.ORG (Jeff Holmes) writes: > a state that when I type 'su' it made me root without > asking for a password. Logging out reset everything > to normal. Anyone had this happen before? The setuid > bit is set (4755) and su is owned by root. ^^^^ ^^^^^^^^^^^^^^^^^^^ I don't know if this is true for Minix, but for most Unixes, if su is executed as root, it doesn't ask for a password. Thus, by making su SUID root, it is executing as root, and thus (thinking that you are root) doesn't ask for a password. -- "Don't find a fault, | Marc Unangst find a remedy." | UUCP: mju@m-net.ann-arbor.mi.us -Henry Ford | UUCP path: ...!uunet!mailrus!clip!m-net!mju ---------------------+ Internet: mju%m-net%clip@umix.cc.umich.edu
wnp@dcs.UUCP (Wolf N. Paul) (12/30/88)
In article <2662@m2-net.UUCP> mju@m-net.UUCP (Marc Unangst) writes: |In article <1971@questar.QUESTAR.MN.ORG> jeff@questar.QUESTAR.MN.ORG (Jeff Holmes) writes: |> a state that when I type 'su' it made me root without |> asking for a password. Logging out reset everything |> to normal. Anyone had this happen before? The setuid |> bit is set (4755) and su is owned by root. | ^^^^ ^^^^^^^^^^^^^^^^^^^ | I don't know if this is true for Minix, but for most Unixes, if su | is executed as root, it doesn't ask for a password. Thus, by making | su SUID root, it is executing as root, and thus (thinking that you are | root) doesn't ask for a password. Actually, SU has to be SUID root, or it would not be able to make you root even if you provided the password. That's where the distinction between the real and effective UID and GID comes in. SU runs with effective UID root, but should check your real UID before deciding whether to ask for the password. -- Wolf N. Paul * 3387 Sam Rayburn Run * Carrollton TX 75007 * (214) 306-9101 UUCP: killer!dcs!wnp ESL: 62832882 DOMAIN: dcs!wnp@killer.dallas.tx.us TLX: 910-380-0585 EES PLANO UD
nagel@paris.ics.uci.edu (Mark Nagel) (12/31/88)
In article <2662@m2-net.UUCP>, mju@m-net (Marc Unangst) writes: |In article <1971@questar.QUESTAR.MN.ORG> jeff@questar.QUESTAR.MN.ORG (Jeff Holmes) writes: |> to normal. Anyone had this happen before? The setuid |> bit is set (4755) and su is owned by root. | ^^^^ ^^^^^^^^^^^^^^^^^^^ |I don't know if this is true for Minix, but for most Unixes, if su |is executed as root, it doesn't ask for a password. Thus, by making |su SUID root, it is executing as root, and thus (thinking that you are |root) doesn't ask for a password. Su *has* to be setuid root, or else how could it perform the necessary setuid for you? It doesn't ask for a password only when the real uid is root. Mark Nagel @ UC Irvine, Dept of Info and Comp Sci ARPA: nagel@ics.uci.edu | The world is coming to an end. UUCP: {sdcsvax,ucbvax}!ucivax!nagel | Please log off.
allbery@ncoast.UUCP (Brandon S. Allbery) (01/05/89)
As quoted from <2662@m2-net.UUCP> by mju@m-net.UUCP (Marc Unangst): +--------------- | I don't know if this is true for Minix, but for most Unixes, if su | is executed as root, it doesn't ask for a password. Thus, by making | su SUID root, it is executing as root, and thus (thinking that you are | root) doesn't ask for a password. +--------------- Eh wot? If su ISN'T setuid root, it can't change you TO root, password or no password! Try again. ++Brandon -- Brandon S. Allbery, comp.sources.misc moderator and one admin of ncoast PA UN*X uunet!hal.cwru.edu!ncoast!allbery ncoast!allbery@hal.cwru.edu comp.sources.misc is moving off ncoast -- please do NOT send submissions direct Send comp.sources.misc submissions to comp-sources-misc@<backbone>.