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CIAC INFORMATION BULLETIN

S-284: Border Gateway Protocol Vulnerabilities

[US-CERT Vulnerability Note VU#929656]

May 7, 2008 16:00 GMT

PROBLEM: Boorder Gateway Protocol (BGP) implementations from multiple vendors including Juniper may not properly handle specially crafted BGP UPDATE messages. These vulnerabilities could allow an unauthenticated, remote attacker to cause a denial of service. Disrupting BGP communication could lead to routing instability.
SYSTEMS
AFFECTED:
Avici Systems, Inc.
Century Systems, Inc.
Hitachi
Juniper Networks, Inc.
Yamaha Corporation
DAMAGE: Remote DoS.
SOLUTION: Upgrade to the appropriate version.

VULNERABILITY
ASSESSMENT:
The risk is LOW. A remote attacker could cause a denial of servcie by injecting a specially crafted BGP UPDATE message into a legitimate BGP session. An attacker with a configured BGP session could attack targets several BGP hops away, or an attacker could spoof TCP traffic.

CVSS 2 BASE SCORE:
   TEMPORAL SCORE:
   VECTOR:
5.4
4.2
(AV:N/AC:H/Au:N/C:N/I:N/A:C/E:POC/RL:OF/RC:C)

LINKS:  
  CIAC BULLETIN: http://www.ciac.org/ciac/bulletins/s-284.shtml
  ORIGINAL BULLETIN: http://www.kb.cert.org/vuls/id/929656#systems
  CVE: CVE-2007-6372

[***** Start US-CERT Vulnerability Note VU#929656 *****]

Vulnerability Note VU#929656

Multiple BGP implementations do not properly handle UPDATE messages

Overview

BGP implementations from multiple vendors including Juniper may not properly handle specially crafted BGP UPDATE messages. These vulnerabilities could allow an unauthenticated, remote attacker to cause a denial of service. Disrupting BGP communication could lead to routing instability.

I. Description

The Border Gateway Protocol (BGP, RFC 4271) is a widely used inter-Autonomous System routing protocol. BGP communication among peer routers is critical to the stable operation of the internet.

Multiple vendors BGP implementations do not properly handle specially crafted BGP UPDATE messages. A vulnerable BGP implementation could drop sessions when processing crafted UPDATE messages. A persistent attack could lead to routing instability (route flapping).

To affect a BGP session, an attacker would need to succesfully inject a specially crafted packet into an existing BGP session or the underlying TCP session (179/tcp). In other words, the attacker would need to have a valid, configured BGP session or be able to spoof TCP traffic.

This vulnerability was first announced as affecting Juniper routers. Further investigation indicates that other vendors are affected by the same or similar issues. Please see the Systems Affected section below.

II. Impact

A remote attacker could cause a denial of service by injecting a specially crafted BGP UPDATE message into a legitimate BGP session. An attacker with a configured BGP session could attack targets several BGP hops away, or an attacker could spoof TCP traffic.

III. Solution

Upgrade

Upgrade your BGP software as appropriate. Please see the Systems Affected section below for information about specific vendors.

In order to send a specially crafted BGP UPDATE message, an attacker must have or spoof a valid BGP connection. To protect against spoofed TCP connections, consider the following workarounds.

Authenticate BGP Traffic
Use TCP MD5 to authenticate BGP traffic (RFC 2385). Only allow BGP traffic from authorized peers.

Restrict BGP Access
Restrict BGP network access to authorized peers. If possible, run BGP on management networks, not transit networks. More information about BGP security (including secure BGP configuration templates) is available from the Team Cymru Reading Room.

Systems Affected

Vendor Status Date Updated
3com, Inc. Unknown 13-Dec-2007
ACCESS Not Vulnerable 1-May-2008
Alcatel Unknown 13-Dec-2007
AT&T Unknown 13-Dec-2007
Avaya, Inc. Unknown 13-Dec-2007
Avici Systems, Inc. Vulnerable 28-Apr-2008
Century Systems Inc. Vulnerable 28-Apr-2008
Charlotte's Web Networks Unknown 13-Dec-2007
Check Point Software Technologies Unknown 13-Dec-2007
Cisco Systems, Inc. Not Vulnerable 6-May-2008
D-Link Systems, Inc. Unknown 13-Dec-2007
Data Connection, Ltd. Unknown 13-Dec-2007
Extreme Networks Unknown 13-Dec-2007
F5 Networks, Inc. Unknown 13-Dec-2007
Force10 Networks, Inc. Not Vulnerable 22-Feb-2008
Foundry Networks, Inc. Not Vulnerable 28-Apr-2008
Fujitsu Not Vulnerable 28-Apr-2008
GNU Zebra Unknown 1-May-2008
Hitachi Vulnerable 28-Apr-2008
Hyperchip Unknown 13-Dec-2007
IBM Corporation Unknown 13-Dec-2007
Ingrian Networks, Inc. Unknown 13-Dec-2007
Intel Corporation Unknown 8-Apr-2008
IP Infusion, Inc. Unknown 1-May-2008
Juniper Networks, Inc. Vulnerable 1-May-2008
Lucent Technologies Unknown 13-Dec-2007
Luminous Networks Unknown 13-Dec-2007
Multinet (owned Process Software Corporation) Unknown 13-Dec-2007
Multitech, Inc. Unknown 13-Dec-2007
Network Appliance, Inc. Not Vulnerable 14-Dec-2007
NextHop Technologies, Inc. Unknown 13-Dec-2007
Nokia Unknown 8-Apr-2008
Nortel Networks, Inc. Unknown 13-Dec-2007
OpenBSD Unknown 22-Feb-2008
Quagga Not Vulnerable 28-Apr-2008
Redback Networks, Inc. Unknown 13-Dec-2007
Riverstone Networks, Inc. Unknown 13-Dec-2007
Sun Microsystems, Inc. Not Vulnerable 28-Apr-2008
Wind River Systems, Inc. Unknown 13-Dec-2007
Yamaha Corporation Vulnerable 28-Apr-2008
ZyXEL Unknown 13-Dec-2007

References

http://www.kb.cert.org/vuls/id/415294
http://tools.ietf.org/html/rfc1771
http://tools.ietf.org/html/rfc4271
http://tools.ietf.org/html/rfc2385
http://tools.ietf.org/html/rfc2439
http://secunia.com/advisories/28100/
http://nvd.nist.gov/nvd.cfm?cvename=CVE-2007-6372
https://www.juniper.net/alerts/viewalert.jsp?actionBtn=Search&txtAlertNumber=PSN-2007-12-008&viewMod%20e=view
http://isc.sans.org/diary.php?storyid=3748
https://puck.nether.net/pipermail/juniper-nsp/2007-December/009294.html
https://puck.nether.net/pipermail/juniper-nsp/2007-December/009299.html
http://osvdb.org/show/osvdb/39157
http://www.securityfocus.com/bid/26869
http://www.frsirt.com/english/advisories/2007/4223
http://securitytracker.com/alerts/2007/Dec/1019100.html
http://www.team-cymru.org/?sec=13&opt=28

Credit

This document was written by Art Manion.

Other Information

Date Public 12/12/2007
Date First Published 05/06/2008 02:30:49 PM
Date Last Updated 05/06/2008
CERT Advisory  
CVE Name CVE-2007-6372
US-CERT Technical Alerts  
Metric 24.49
Document Revision 45

[***** End US-CERT Vulnerability Note VU#929656 *****]

   

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