Multiple Security Vulnerabilities in Solaris TCP (see tcp(7P)) Implementation May Lead to a Denial of Service (DoS) Condition

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Multiple Security Vulnerabilities in Solaris TCP (see tcp(7P)) Implementation May Lead to a Denial of Service (DoS) Condition

1. Impact

Multiple security vulnerabilities exist in the Solaris TCP (see tcp(7P)) implementation due to the lack of resource control mechanisms. These issues may allow a remote privileged user with real IP addresses or subnet to easily cause certain network services on the affected system to become unresponsive, which is a type of Denial of Service (DoS). The extent of the impact depends on the network application.

These issues are also referenced in the following documents:

CERT-FI Advisory on the Outpost24 TCP Issues [FICORA #193744] at https://www.cert.fi/haavoittuvuudet/2008/tcp-vulnerabilities.html

CVE CVE-2008-4609 at http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-4609

US-CERT VU#723308 at http://www.kb.cert.org/vuls/id/723308

Sun acknowledges with thanks, Jack C. Louis and Robert E. Lee of Outpost24, and CERT-FI for bringing these issues to our attention.

2. Contributing Factors

These issues can occur in the following releases:

SPARC Platform

• Solaris 8
• Solaris 9
• Solaris 10
• OpenSolaris based upon builds snv_01 through snv_130

x86 Platform

• Solaris 8
• Solaris 9
• Solaris 10
• OpenSolaris based upon builds snv_01 through snv_130

Notes:

1. Solaris 8 entered EOSL Phase 2 on 1 April 2009. Entitlement to patches developed on or after 1 April 2009 requires the purchase of the Solaris 8 Vintage Patch Service. See Note in section 5 for more details.

2. Solaris systems that are not listening to any connections, or which are configured to allow connections only from trusted hosts are
not impacted by these issues.

3. OpenSolaris distributions may include additional bug fixes above and beyond the build from which it was derived. The base build can be derived as follows:-

$ uname -v
snv_111

3. Symptoms

Should the described issues occur, network services on a system may become unresponsive. Services would recover with time once the attack is stopped. If a described issue occurs, Solaris commands such as netstat (see netstat(1M)) may indicate source IP addresses of the attack.

4. Workaround

On Solaris 10 and OpenSolaris, ipfilter (see ipfilter(5)) may be used to block connections from source IP addresses of the attacks.

5. Resolution

This issue is addressed in the following releases:

SPARC Platform

• OpenSolaris based upon builds snv_131 or later

x86 Platform

• OpenSolaris based upon builds snv_131 or later

A final resolution is pending completion.

Note 1: In addition to the above Resolution, the following new ndd(1M) parameters are available in OpenSolaris, which can be used to limit the usage of memory resources by a given network service.


Usage is the following.

1. To limit the amount of memory consumed by a web server application on port 80.

# ndd -set /dev/tcp tcp_listener_limit_conf_add 80:<n>

where <n> is a number greater than 0.

The above will limit the number of TCP connections the web server can have concurrently such that the maximum amount of memory consumed does not exceed 1/n of the system memory. Note that this is only an approximation.

2. To remove the limit on port 80:

# ndd -set /dev/tcp tcp_listener_limit_conf_del 80

3. To show the current list of listener limit configurations:

# ndd /dev/tcp tcp_listener_limit_conf

Note 2: The READMEs of Solaris 8 patches developed on or after 1 April 2009 are available to all customers however Solaris 8 entered EOSL Phase 2 on April 1, 2009 and thus entitlement for these patches, including those that fix security vulnerabilities, requires the purchase of the Solaris 8 Vintage Patch Service. More information about the Solaris 8 Vintage Patch Service is available at:


For more information on Security Sun Alerts, see Technical Instruction ID 213557.

This Sun Alert notification is being provided to you on an "AS IS" basis. This Sun Alert notification may contain information provided by third parties. The issues described in this Sun Alert notification may or may not impact your system(s). Sun makes no representations, warranties, or guarantees as to the information contained herein. ANY AND ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT, ARE HEREBY DISCLAIMED. BY ACCESSING THIS DOCUMENT YOU ACKNOWLEDGE THAT SUN SHALL IN NO EVENT BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, PUNITIVE, OR CONSEQUENTIAL DAMAGES THAT ARISE OUT OF YOUR USE OR FAILURE TO USE THE INFORMATION CONTAINED HEREIN. This Sun Alert notification contains Sun proprietary and confidential information. It is being provided to you pursuant to the provisions of your agreement to purchase services from Sun, or, if you do not have such an agreement, the Sun.com Terms of Use. This Sun Alert notification may only be used for the purposes contemplated by these agreements.

Copyright 2000-2009 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, CA 95054 U.S.A. All rights reserved.


Modification History

11-Dec-2009: Updated Contributing Factors and Resolution sections for OpenSolaris
19-Jan-2010: Updated Impact section with US-CERT notification

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