#101658: Sun TCP Connections May Experience Performance Degradation If Certain ICMP Error Messages Are Received (formerly Document ID: 57746)

Sun(sm) Alert Notification

Sun Alert ID: 101658 (formerly 57746)
Synopsis: Sun TCP Connections May Experience Performance Degradation If Certain ICMP Error Messages Are Received
Category: Security
Product: Solaris 9 Operating System, Solaris 10 Operating System, Solaris 7 Operating System, Solaris 8 Operating System
BugIDs: 5084452
Avoidance: Patch
State: Resolved
Date Released: 12-Apr-2005, 07-Dec-2006
Date Closed: 07-Dec-2006
Date Modified: 07-Jun-2005, 02-Feb-2006, 03-Mar-2006, 21-Mar-2006, 12-Apr-2006, 29-Nov-2006, 07-Dec-2006

1. Impact

This Sun Alert describes the Sun specific impact of the issues described in the Internet-Draft (I-D) titled "ICMP attacks against TCP" written by Fernando Gont. The I-D describes how TCP(7P) connections could be reset and disconnected as a result of ICMP(7P) error messages. Solaris will not drop established TCP connections based on ICMP errors. There is a theoretical possibility that a TCP connection which is in the process of being set up could be terminated before being established. However, there is no risk of data corruption or compromise in this scenario.

The draft also describes ICMP messages which could impact the performance of existing TCP connections. This issue affects all current versions of Solaris and thus Sun plans on improving how ICMP errors are handled to further mitigate the impact of such ICMP messages.

This issue is also described in the following documents:

IETF Internet Draft at http://www.ietf.org/internet-drafts/draft-gont-tcpm-icmp-attacks-03.txt

CERT Vulnerability Note VU#222750 at http://www.kb.cert.org/vuls/id/222750

CVEs CAN-2004-0790 at http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2004-0790

CVEs CAN-2004-0791 at http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2004-0791

2. Contributing Factors

This issue can occur in the following releases:

SPARC Platform

Solaris 7 without patch 106541-44
Solaris 8 without patch 116965-19
Solaris 9 without patch 118305-08
Solaris 10 without patch 118822-27

x86 Platform

Solaris 7 without patch 106542-43
Solaris 8 without patch 116966-18
Solaris 9 without patch 117470-07
Solaris 10 without patch 118844-28

3. Symptoms

In order to verify if ICMP error messages are being sent to a specific system on the network, a network monitoring tool such as snoop(1M) can be used from either the specific system or another system on the same network.

The following command can be run (as "root"):

    # snoop -o <output-file>

Afterwards, the snoop(1M) utility can display the packets captured in the "output-file" using the "-v" and "-i" options, as in:

    # snoop -v -i output-file icmp icmp6

and inspect the output for ICMP packets which will look similar to the following:

    ICMP:  ----- ICMP Header -----
    ICMP:
    ICMP:  Type = 0 (Echo reply)
    ICMP:  Code = 0 (ID: 5417 Sequence number: 0)
    ICMP:  Checksum = be96
    ICMP:

If the "Type" value and the "Code" value (for multiple packets) are equal to any of the following combinations:

    Type    Code    Name                            
    ----    ----    -----------------               
     4       0      Source Quench                  
     3       *      Net/Host/Protocol/Port Unreachable, etc.
     5       *      Redirect                      
     6       0      Alternate Host Address       
     11      *      Time Exceeded  
     12      *      Parameter Problem

then the system may be the target of the described ICMP issue.

Solution Summary

Top

4. Relief/Workaround

There is no workaround for this issue. Please see the Resolution section below.

5. Resolution

This issue is addressed in the following releases:

SPARC Platform

Solaris 7 with patch 106541-44 or later
Solaris 8 with patch 116965-19 or later
Solaris 9 with patch 118305-08 or later
Solaris 10 with patch 118822-27 or later

x86 Platform

Solaris 7 with patch 106542-43 or later
Solaris 8 with patch 116966-18 or later
Solaris 9 with patch 117470-07 or later
Solaris 10 with patch 118844-28 or later

Change History

07-Jun-2005:

Correction to CERT URL made in Impact section

02-Feb-2006:

Updated Contributing Factors and Resolution sections

03-Mar-2006:

Updated Contributing Factors and Resolution sections

21-Mar-2006:

Updated Contributing Factors and Resolution sections

12-Apr-2006:

Updated Contributing Factors and Resolution sections

29-Nov-2006:

Updated Contributing Factors and Resolution sections

07-Dec-2006:

Updated Contributing Factors and Resolution sections
State: Resolved

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