Rapid7 VulnDB

SMBLoris NBSS Denial of Service

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SMBLoris NBSS Denial of Service

Disclosed
06/29/2017
Created
05/30/2018

Description

The SMBLoris attack consumes large chunks of memory in the target by sending SMB requests with the NetBios Session Service(NBSS) Length Header value set to the maximum possible value. By keeping these connections open and initiating large numbers of these sessions, the memory does not get freed, and the server grinds to a halt. This vulnerability was originally disclosed by Sean Dillon and Zach Harding. DISCALIMER: This module opens a lot of simultaneous connections. Please check your system's ULIMIT to make sure it can handle it. This module will also run continuously until stopped.

Author(s)

  • thelightcosine
  • Adam Cammack <adam_cammack@rapid7.com>

Development

References

Module Options

To display the available options, load the module within the Metasploit console and run the commands 'show options' or 'show advanced':

msf > use auxiliary/dos/smb/smb_loris
msf auxiliary(smb_loris) > show actions
    ...actions...
msf auxiliary(smb_loris) > set ACTION < action-name >
msf auxiliary(smb_loris) > show options
    ...show and set options...
msf auxiliary(smb_loris) > run 

Time is precious, so I don’t want to do something manually that I can automate. Leveraging the Metasploit Framework when automating any task keeps us from having to re-create the wheel as we can use the existing libraries and focus our efforts where it matters.

– Jim O’Gorman | President, Offensive Security

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