A Security Vulnerability in Solaris 10 involving the sendfilev() system call could result in Denial of Service (DoS) due to System Panic

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A Security Vulnerability in Solaris 10 involving the sendfilev() system call could result in Denial of Service (DoS) due to System Panic

1. Impact

A security vulnerability in Solaris 10 related to the sendfilev() system call may allow a user who has the ability to create pages that are hosted on a Solaris 10 system using Apache 2.2.x to create a carefully crafted web page which could cause a system panic resulting in a Denial of Service (DoS) condition.
 
In addition, it may be possible for a local unprivileged user to be able to panic the system with a specially crafted program which calls the sendfile() system call (using either the sendfilev(3EXT) library routine or else directly).

2. Contributing Factors

This issue can occur in the following releases:

SPARC Platform

• Solaris 10 without patch 137111-04
• OpenSolaris based upon builds snv_01 through snv_95

x86 Platform

• Solaris 10 without patch 137112-04
• OpenSolaris based upon builds snv_01 through snv_95

Note: Solaris 8 and 9 are not impacted by this issue.

Note: 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 -a
SunOS  phys-node-1 5.11 snv_86 i86pc i386 i86pc

Note: The issue may be triggered by Apache 2.2.x web servers when compiled without certain compiler switches. Apache binaries shipped with Solaris are correctly compiled to avoid this issue.

3. Symptoms

The system panics when kmem_flags are not set with a data fault, or alignment error (Sparc) or a General Protection Fault (x86/x64) from a random thread dealing with Streams dblk_t data types.
  
On a system with kmem_flags set to audit and redzone checking, (kmem_flags = 0x7 may be used), the system panics when kernel memory corruption is detected.

4. Workaround

There is no workaround for this issue, unless the issue is triggered by Apache 2.2.x.

If the issue is triggered by Apache 2.2.x, the following is recommended:
   
Disable the use of sendfilev() in Apache by locating all the 'httpd.conf' files for all the Apache servers on the system and adding the following line:
   

then stop and restart all Apache instances.

5. Resolution

This issue is addressed in the following releases:

SPARC Platform:

• Solaris 10 with patch 137111-04 or later
• OpenSolaris based upon builds snv_96 or later

x86 Platform:

• Solaris 10 with patch 137112-04 or later
• OpenSolaris based upon builds snv_96 or later

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.

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Modification History

26-Aug-2008: Updated Contributing Factors and Workaround sections for Apache version clarification (2.2.x)

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