hi i have written small script which will login 2 two different users with su but if we run from normal user it prompts for password so
i chnaged the owner of script to root and added setuid bit
with
chmod u+s <script_name>
I have a binary. It is having the following permissions
rws rws rwx mqm:mqm runmqtrm
The same program on another machine is
rws rws rwx root: mqm runmqtrm
This program is a setuid program.
This is what my understanding is. Whatever user the program is started under, it will finally be... (0 Replies)
hi all,
i have a critical and specific problem with respect to set uid bit on user and the dll's
for a binary, (under the userid A)
it needs libraries from /usr/lib and informix libraries from $INFORMIXDIR/lib/esql
but this binary should be kicked off from id B,
hence s-bit on user is... (5 Replies)
Hi,
I am compiling Qt-4.7 for 32-bit on 64-bit (x86_64) Ubuntu 8.04 desktop. I have installed all the 32-bit libraries (/lib32 and /usr/lib32) through getlibs and "apt-get install ia32-libs". But I am getting the following error while configuring the qt project as:
./configure -platform... (2 Replies)
Hi,
OS : Linux
I have an executable (P1) owned by user say "abcd" and the setuid bit is set. And there is another executable (P2) which brings up the process (P1).
When the setuid bit is set, the process P1 is failing, if the setuid bit is not set there is no issue.
I was wondering if... (6 Replies)
Dear all,
I am newbie with linux, i dont understand any code. I have googled a long time. Please help me explain about setuid bit on linux (Centos 6)
Here:
1/ I chmod u+s for /sbin/iptables but normal user still cannot perform command (ex: /sbin/iptables -L)
2/Someone says : setuid only... (6 Replies)
Hi,
Here is the issue. From the program snippet I have Base: 0x1800000000, Size: 0x3FFE7FFFFFFFF which are of 40 and 56 bits. SO I used use bignum to do the math but summing them up I always failed having correct result.
perl interpreter info,
perl, v5.8.8 built for... (0 Replies)
Just learning about the privilege escalation method provided by setuid. Correct me if I am wrong but what it does is change the uid of the current process to whatever uid I set. Right ?
So what stops me from writing my own C program and calling setuid(0) within it and gaining root privileges ?
... (2 Replies)
Discussion started by: sreyan32
2 Replies
LEARN ABOUT CENTOS
setuid
SETUID(2) Linux Programmer's Manual SETUID(2)NAME
setuid - set user identity
SYNOPSIS
#include <sys/types.h>
#include <unistd.h>
int setuid(uid_t uid);
DESCRIPTION
setuid() sets the effective user ID of the calling process. If the effective UID of the caller is root, the real UID and saved set-user-ID
are also set.
Under Linux, setuid() is implemented like the POSIX version with the _POSIX_SAVED_IDS feature. This allows a set-user-ID (other than root)
program to drop all of its user privileges, do some un-privileged work, and then reengage the original effective user ID in a secure man-
ner.
If the user is root or the program is set-user-ID-root, special care must be taken. The setuid() function checks the effective user ID of
the caller and if it is the superuser, all process-related user ID's are set to uid. After this has occurred, it is impossible for the
program to regain root privileges.
Thus, a set-user-ID-root program wishing to temporarily drop root privileges, assume the identity of an unprivileged user, and then regain
root privileges afterward cannot use setuid(). You can accomplish this with seteuid(2).
RETURN VALUE
On success, zero is returned. On error, -1 is returned, and errno is set appropriately.
ERRORS
EAGAIN The uid does not match the current uid and uid brings process over its RLIMIT_NPROC resource limit.
EPERM The user is not privileged (Linux: does not have the CAP_SETUID capability) and uid does not match the real UID or saved set-user-ID
of the calling process.
CONFORMING TO
SVr4, POSIX.1-2001. Not quite compatible with the 4.4BSD call, which sets all of the real, saved, and effective user IDs.
NOTES
Linux has the concept of the file system user ID, normally equal to the effective user ID. The setuid() call also sets the file system
user ID of the calling process. See setfsuid(2).
If uid is different from the old effective UID, the process will be forbidden from leaving core dumps.
The original Linux setuid() system call supported only 16-bit user IDs. Subsequently, Linux 2.4 added setuid32() supporting 32-bit IDs.
The glibc setuid() wrapper function transparently deals with the variation across kernel versions.
SEE ALSO getuid(2), seteuid(2), setfsuid(2), setreuid(2), capabilities(7), credentials(7)COLOPHON
This page is part of release 3.53 of the Linux man-pages project. A description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
Linux 2010-11-22 SETUID(2)