Security Vulnerability in the Solaris NFS Server Security Modes (nfssec(5)) may Lead to Unauthorized Access to Shared Resources

Security vulnerability in the Solaris NFS server security modes (nfssec(5)) may lead to unauthorized access to shared resources.

Document Audience: PUBLIC
Document ID: 253588
Title: Security Vulnerability in the Solaris NFS Server Security Modes (nfssec(5)) may Lead to Unauthorized Access to Shared Resources
Copyright Notice: Copyright 2009 Sun Microsystems, Inc. All Rights Reserved
Update Date: Mon Mar 09 00:00:00 MDT 2009

Solution TypeSun Alert

Solution 253588 : Security Vulnerability in the Solaris NFS Server Security Modes (nfssec(5)) may Lead to Unauthorized Access to Shared Resources


Bug ID

6359212

Product

Solaris 10 Operating System OpenSolaris

Date of Resolved Release

09-Mar-2009

SA Document Body

Security vulnerability in the Solaris NFS server security modes (nfssec(5)) may lead to unauthorized access to shared resources:

1. Impact

A security vulnerability in the Solaris NFS server may lead to unauthorized access to file systems shared via NFS if those resources are shared using a combination of "none" (AUTH_NONE) and "sys" (AUTH_SYS) (see nfssec(5)) security modes.

2. Contributing Factors

This issue can occur in the following releases:

SPARC Platform
  • Solaris 10 without patch 139462-02
  • OpenSolaris based upon builds snv_01 through snv_110
x86 Platform
  • Solaris 10 without patch 139463-02
  • OpenSolaris based upon builds snv_01 through snv_110
Note 1: Solaris 8 and Solaris 9 are not impacted by this issue.

Note 2: Only NFS servers which export shares with AUTH_NONE used in combination with the security mode AUTH_SYS are impacted by this issue. To determine if a system is configured to run as an NFS server (see smf(5)), the following command can be used:

$ svcs nfs/server
STATE STIME FMRI
online 14:30:59 svc:/network/nfs/server:default

To determine if a system exports shares that have AUTH_NONE used in combination with AUTH_SYS, run the following command on the server (see share_nfs(1M)):

$ share /var/tmp
sec=sys,rw=authorized-host,sec=none,ro

If the output of the share(1M) command includes NFS shares with "sec=sys" and "sec=none", then the NFS server shares resources with AUTH_NONE used in combination with the security mode AUTH_SYS.

Note 3: OpenSolaris distributions may include additional bug fixes above and beyond the build from which it was derived. To determine the base build of OpenSolaris, the following command can be used:

$ uname -v
snv_86

3. Symptoms

There are no predictable symptoms that would indicate the described vulnerability has been exploited to gain unauthorized access to exported data.

4. Workaround

To avoid this issue until patches can be applied, do not export NFS shares on the NFS server using AUTH_NONE and AUTH_SYS in combination.

5. Resolution

This issue is addressed in the following releases:

SPARC Platform
  • Solaris 10 with patch 139462-02 or later
  • OpenSolaris based upon builds snv_111 or later
x86 Platform
  • Solaris 10 with patch 139463-02 or later
  • OpenSolaris based upon builds snv_111 or later
For more information on Security Sun Alerts, see Technical Instruction ID 213557 .

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