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Date:      Wed, 19 Mar 2003 17:13:06 -0500
From:      Mike Tancsa <mike@sentex.net>
To:        security@FreeBSD.org
Subject:   Re: Fwd: EEYE: XDR Integer Overflow
Message-ID:  <5.2.0.9.0.20030319170809.082d2c98@marble.sentex.ca>
In-Reply-To: <5.2.0.9.0.20030319155420.080cbab8@marble.sentex.ca>

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One of the patches seems to deal with


===================================================================
RCS file: /cvs/glibc/libc/sunrpc/rpc/xdr.h,v
retrieving revision 1.26
retrieving revision 1.27
diff -u -r1.26 -r1.27
--- libc/sunrpc/rpc/xdr.h       1999/10/09 21:26:03     1.26
+++ libc/sunrpc/rpc/xdr.h       2002/12/16 02:05:49     1.27
@@ -126,7 +126,7 @@
         /* returns bytes off from beginning */
         bool_t (*x_setpostn) (XDR *__xdrs, u_int __pos);
         /* lets you reposition the stream */
-       int32_t *(*x_inline) (XDR *__xdrs, int __len);
+       int32_t *(*x_inline) (XDR *__xdrs, u_int __len);
         /* buf quick ptr to buffered data */
         void (*x_destroy) (XDR *__xdrs);
         /* free privates of this xdr_stream */
@@ -139,7 +139,7 @@
      caddr_t x_public;          /* users' data */
      caddr_t x_private;         /* pointer to private data */
      caddr_t x_base;            /* private used for position info */
-    int x_handy;               /* extra private word */
+    u_int x_handy;             /* extra private word */
    };

  /*



NetBSD is not vulnerable due to, "The length types of the various 
xdr*_getbytes functions were made consistent somewhere back in 1997 (all 
u_int), so we're not vulnerable in that area."

However, FreeBSD still seems to have the above as an int as well.  So it 
appears to be vulnerable ?

         ---Mike




At 03:54 PM 19/03/2003 -0500, Mike Tancsa wrote:

>Anyone know if this effects FreeBSD ? There is no mention in the CERT 
>advisory.
>
>         ---Mike
>
>
>>Mailing-List: contact bugtraq-help@securityfocus.com; run by ezmlm
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>>From: "Marc Maiffret" <marc@eeye.com>
>>To: "BUGTRAQ" <BUGTRAQ@securityfocus.com>
>>Subject: EEYE: XDR Integer Overflow
>>Date: Wed, 19 Mar 2003 12:20:14 -0800
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>>
>>XDR Integer Overflow
>>
>>Release Date:
>>March 19, 2003
>>
>>Severity:
>>High (Remote Code Execution/Denial of Service)
>>
>>Systems Affected:
>>
>>Sun Microsystems Network Services Library (libnsl)
>>BSD-derived libraries with XDR/RPC routines (libc)
>>GNU C library with sunrpc (glibc)
>>
>>Description:
>>
>>XDR is a standard for the description and encoding of data which is used
>>heavily in RPC implementations. Several libraries exist that allow a
>>developer to incorporate XDR into his or her applications. Vulnerabilities
>>were discovered in these libraries during the testing of new Retina auditing
>>technologies developed by the eEye research department.
>>
>>ADAM and EVE are two technologies developed by eEye to remotely and locally
>>audit applications for the existence of common vulnerabilities. During an
>>ADAM audit, an integer overflow was discovered in the SUN Microsystems XDR
>>library. By supplying specific integer values in length fields during an RPC
>>transaction, we were able to produce various overflow conditions in UNIX RPC
>>services.
>>
>>Technical Description:
>>
>>The xdrmem_getbytes() function in the XDR library provided by Sun
>>Microsystems contains an integer overflow. Depending on the location and use
>>of the vulnerable xdrmem_getbytes() routine, various conditions may be
>>presented that can permit an attacker to remotely exploit a service using
>>this vulnerable routine.
>>
>>For the purpose of signature development and further security research a
>>sample session is included below that replicates an integer overflow in the
>>rpcbind shipped with various versions of the Solaris operating system.
>>
>>char evil_rpc[] =
>>
>>"\x23\x0D\xF6\xD2\x00\x00\x00\x00\x00\x00\x00\x02\x00\x01\x86"
>>"\xA0\x00\x00\x00\x02\x00\x00\x00\x05\x00\x00\x00\x01\x00\x00"
>>"\x00\x20\x3D\xD2\xC9\x9F\x00\x00\x00\x09\x6C\x6F\x63\x61\x6C"
>>"\x68\x6F\x73\x74\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
>>"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\x86"
>>"\xa0\x00\x00\x00\x02\x00\x00\x00\x04"
>>"\xFF\xFF\xFF\xFF" // RPC argument length
>>"EEYECLIPSE2003";
>>
>>Vendor Status:
>>
>>Sun Microsystems was contacted on November 13, 2002 and CERT was contacted
>>shortly afterwards. Vendors believed to be vulnerable were contacted by CERT
>>during a grace period of several months. Due to some difficulties
>>communicating with vendors, after rescheduling several times a release date
>>was set for March 18, 2003.
>>
>>eEye recommends obtaining the necessary patches or updates from vendors as
>>they become available after the release of this and the CERT advisory.
>>
>>For a list of vendors and their responses, please review the CERT advisory
>>at: http://www.cert.org/advisories/CA-2003-10.html
>>
>>You can find the latest copy of this advisory, along with other eEye
>>research at http://www.eeye.com/.
>>
>>Credit:
>>Riley Hassell - Senior Research Associate
>>
>>Greetings:
>>Liver destroyers of the world:
>>Barnes (DOW!), FX, and last but definitely not least, Heather and Jenn.
>>
>>Copyright (c) 1998-2003 eEye Digital Security
>>Permission is hereby granted for the redistribution of this alert
>>electronically. It is not to be edited in any way without express consent of
>>eEye. If you wish to reprint the whole or any part of this alert in any
>>other medium excluding electronic medium, please e-mail alert@eEye.com for
>>permission.
>>
>>Disclaimer
>>The information within this paper may change without notice. Use of this
>>information constitutes acceptance for use in an AS IS condition. There are
>>NO warranties with regard to this information. In no event shall the author
>>be liable for any damages whatsoever arising out of or in connection with
>>the use or spread of this information. Any use of this information is at the
>>user's own risk.
>>
>>Feedback
>>Please send suggestions, updates, and comments to:
>>
>>eEye Digital Security
>>http://www.eEye.com
>>info@eEye.com
>
>--------------------------------------------------------------------
>Mike Tancsa,                                      tel +1 519 651 3400
>Sentex Communications,                            mike@sentex.net
>Providing Internet since 1994                    www.sentex.net
>Cambridge, Ontario Canada                         www.sentex.net/mike
>
>
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