Bug 34813 - (CVE-2001-0414) CVE-2001-0414 ntpd security hole
CVE-2001-0414 ntpd security hole
Product: Red Hat Linux
Classification: Retired
Component: ntp (Show other bugs)
i386 Linux
high Severity medium
: ---
: ---
Assigned To: Preston Brown
Brian Brock
: Security
Depends On:
  Show dependency treegraph
Reported: 2001-04-04 23:54 EDT by James Brents
Modified: 2018-03-01 10:07 EST (History)
8 users (show)

See Also:
Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of:
Last Closed: 2001-04-06 14:36:45 EDT
Type: ---
Regression: ---
Mount Type: ---
Documentation: ---
Verified Versions:
Category: ---
oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

Attachments (Terms of Use)
Patch for Rawhide ntp-4.0.99k-13 -- that srpmworks apparently if you have RH7 or recent rawhide, RH 6.0 doesn't like it.. (850 bytes, patch)
2001-04-05 08:49 EDT, matti aarnio
no flags Details | Diff
xntp3 (RHL62) patch (864 bytes, patch)
2001-04-05 10:19 EDT, Pekka Savola
no flags Details | Diff

  None (edit)
Description James Brents 2001-04-04 23:54:18 EDT
From Bugzilla Helper:
User-Agent: Mozilla/5.0 (X11; U; Linux 2.4.3 i686; en-US; 0.8.1)

ntpd security hole allowing the execution of arbitrary code.

Reproducible: Always
Steps to Reproduce:
Run exploit as shown on bugtraq

Actual Results:  ntpd crashed. Though said exploit did not successfully
execute /tmp/sh as was expected.

Expected Results:  Ntpd to not be affected

Used ntp-4.0.99j-7 with RH7 for testing.

Bugtraq post: http://www.securityfocus.com/archive/1/174011
Comment 1 Pekka Savola 2001-04-05 01:02:15 EDT
For the record, FreeBSD has fixed it (and made the exploitation attempts logged) as follows:

Comment 2 Daniel Roesen 2001-04-05 07:35:24 EDT
As far as I understood (from Bugtraq) this also affects RH 6 xntpd, right?
Logging breakin attempts would be very good, nod.
Comment 3 matti aarnio 2001-04-05 08:49:47 EDT
Created attachment 14723 [details]
Patch for Rawhide ntp-4.0.99k-13 -- that srpmworks apparently if you have RH7 or recent rawhide, RH 6.0 doesn't like it..
Comment 4 Pekka Savola 2001-04-05 10:18:10 EDT
Yeah, that's caused by the ugly glibc-2.2 hack (patch0).

But anyway, you should use xntp3 for RHL62 when upgrading.  As the name changed,
you might have
a nasty surprise as xntp3 -> ntp upgrade lost the syslevel config ('chkconfig
--list | grep ntp').

Attached is my patch I used for xntp3.  Very similar.
Comment 5 Pekka Savola 2001-04-05 10:19:07 EDT
Created attachment 14727 [details]
xntp3 (RHL62) patch
Comment 6 Preston Brown 2001-04-05 13:51:27 EDT
we are working on a fix.
Comment 7 Craig Kelley 2001-04-05 15:51:02 EDT
Debian checked in security patches yesterday for potato -- you may want to take
a look at the patch.
Comment 8 Pekka Savola 2001-04-05 16:04:02 EDT
The debian patch is 100% same.  I think it has originated on ntp-hackers list or the like.

ALSO, when creating the errata for xntp3, please also fix the following (possible) problems
(by Jarno Huuskonen):

diff -uNr xntp3-5.93/libntp/msyslog.c xntp3-5.93.sec/libntp/msyslog.c
--- xntp3-5.93/libntp/msyslog.c Tue Aug 12 09:21:29 1997
+++ xntp3-5.93.sec/libntp/msyslog.c     Wed Oct  4 19:53:08 2000
@@ -141,7 +141,7 @@
          *n++ = '\n';
        *n = '\0';
-       vsprintf(buf, nfmt, ap);
+       vsnprintf(buf, 1024, nfmt, ap);
 #if !defined(VMS) && !defined (SYS_VXWORKS)
        if (syslogit)
 #ifndef SYS_WINNT
diff -uNr xntp3-5.93/xntpd/ntp_io.c xntp3-5.93.sec/xntpd/ntp_io.c
--- xntp3-5.93/xntpd/ntp_io.c   Fri Mar 13 03:47:05 1998
+++ xntp3-5.93.sec/xntpd/ntp_io.c       Wed Oct  4 19:54:56 2000
@@ -915,7 +915,7 @@
              fd, addr->sin_family, (int)ntohs(addr->sin_port),
              IN_CLASSD(ntohl(addr->sin_addr.s_addr)), flags);
-      msyslog(LOG_ERR, buff);
+      msyslog(LOG_ERR, "%s", buff);
Comment 9 Chris Evans 2001-04-05 17:10:09 EDT
And can RH7.1 ship with a kosher version please:)
Comment 10 Andrew Bartlett 2001-04-05 18:04:54 EDT
I'm not sure I entirely understand how NTP works (I just install it, specify a
server a watch my clock stay in sync) but it would be good if it didn't offer
service to others by default - ie it operated as a client only.  

Further, is there any reason the server component needs to run as root?  It only
reads the current time, it seems that its only the client that need special
rights (update the system clock)?
Comment 11 Pekka Savola 2001-04-06 02:06:27 EDT
The server updates it's own clock too.

Root privileges can be dropped if the capability to change system clock is held
back.  This can be
done using kernel capabilities.  I've made an RPM package to do this (patch and
part of the 
packaging by Chris Wing and Jarno Huuskonen), but it requires kernel >= 2.2.18. 

I hope ntp no longer runs as root in future RHL releases.
Comment 12 Andrew Bartlett 2001-04-06 03:13:12 EDT
Well as RedHat needs to ship 2.2.19 anyway (ptrace, plus about 17 other security
fixes) it shouldn't be a problem.

Can you post a link to the patch/package?
Comment 13 Andrew Bartlett 2001-04-06 09:11:44 EDT
Also, as metioned on bugtraq - http://www.securityfocus.com/archive/1/174372

Could RedHat ship with

restrict default ignore

in the ntp.conf by default?
Comment 14 Pekka Savola 2001-04-06 11:22:32 EDT
I'm interested how that command _really_ affects the behaviour.  Specifically,
I'd like to know whether that command drops the replies to local ntp queries
too or not.  And if not, how big the time window there is for someone to spoof
the reply.

As for the droproot + chroot src.rpm, it's available at
You will also need libcap library from the same location (original from PLD; not
100% optimized
for RHL at this point, but works). 

Comment 15 Pekka Savola 2001-04-06 14:36:41 EDT
Please also see:

  Modified files:        (Branch: RELENG_4)
    contrib/ntp/ntpd     ntp_control.c 
  MFC revs 1.3 and 1.4:
    - Correct off-by-one error and buffer underflow from previous fix
    - int -> unsigned char fixes
    - Prevent potential syslog DoS
Comment 16 James Brents 2001-04-09 12:06:45 EDT
Bug fixxed, update notices sent, marking resolved.

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