Security Advisory 0025
Date: October 17th, 2016
|1.0||October 17th, 2016||Initial Release|
|1.1||October 18th, 2016||Affected platforms section is expanded|
Affected Platforms: DCS-7050 series only - 7050S, 7050T, 7050Q platforms (7050X series of products is not affected). None of the other platform families are affected.
Affected Software Version: All EOS releases after EOS-4.15.2F
CVSS v2 Base Score: 7.8 (High)
Impact: This advisory is to document a security vulnerability that affects Arista products. On the DCS-7050 series, sending certain packets to the control plane can cause the device to unexpectedly reboot.
After the switch reload, "show reload cause" will have a backtrace with the following line that is indicative of this vulnerability.
[ 2330.476815] strata-dma: sobmh_ts_offset_set::unsupported sobmh version=0x5
[ 2330.752624] ------------[ cut here ]------------
[ 2330.754711] kernel BUG at /usr/include/CpuFabric/strata-dcb.h:509!
BUG158250 tracks this vulnerability. A fix for this issue is available in versions 4.15.8M, 4.16.7M, 4.17.0F.
Resolution: It is recommended to upgrade EOS to versions with the fix (4.15.8M, 4.16.7M or 4.17.0F) or install the patch provided on affected versions of EOS.
Patch file download URL: CVE-2016-6894-hotfix.swix
Sha256 sum is:
[admin@switch flash]$ sha256sum CVE-2016-6894-hotfix.swix
- This hotfix can be installed on all affected versions of EOS.
- Installing the patch will restart the forwarding agent that could lead to a momentary disruption in traffic forwarding.
- A reload of the switch is not required for the patch to take effect
Instructions to install the patch
- Download the patch file and copy the file to the extension partition of the switch using one of the supported file transfer protocols:
switch#copy scp://10.10.0.1/CVE-2016-6894-hotfix.swix extension: switch#verify /sha256 extension:CVE-2016-6894-hotfix.swixVerify that the checksum value returned by the above command matches the provided SHA256 checksum for the file
- Install the patch using the extension command. The patch takes effect immediately at the time of installation.
- Verify that the patch is installed using the following commands:
switch#show extensions Name Version/Release Status extension ------------------------------------------ ------------------------- ------ ---- CVE-2016-6894-hotfix.swix 2.7.0/3450908.idcaldwellS A, I 1 A: available | NA: not available | I: installed | NI: not installed | F: forced
- Make the patch persistent across reloads. This ensures that the patch is installed as part of the boot-sequence. The patch will not install on EOS versions with the security fix.
switch#copy installed-extensions boot-extensions switch#show boot-extensions CVE-2016-6894-hotfix.swix
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