Penetration Testing mailing list archives
Re: Port scan causing system crashes
From: Anthony Kim <Anthony.Kim () VWCREDIT COM>
Date: Thu, 12 Jun 2003 14:02:43 -0500
On Thu, Jun 12, 2003, steve.x.jones () royalmail com wrote:
Hello Please can you help? Has any-one else out there had issues with NMAP port scans (or any other port scanner) causing systems to crash? I use Nessus to baseline the security of our systems and have twice had problems caused by the NMAP port scan on clustered unix boxes running our enterprise applications. NOTE - it was the initial port scan that caused the problems, not the subsequent vulnerability assessment. I've done a quick Google search and found confirmation for one of the systems - BUGTRAQ Vulnerability 3358, "IBM HACMP Port Scan Denial of Service Vulnerability", the other was a bespoke app running on some HP UX boxes. Does any-one know of other systems that fall over with a simple port scan? Up til now I've been running port scans happily across our subnets to look for rogue FTP, SMTP, HTTP etc, obviously I'll have to take more care now...
ISS NFS scans totally fsck up our HP-UX NFS. We believe the problem lies in client biod's and cacheing. After a scan, NFS writes fail while NFS reads work fine. To fix the problem, on each client we remount using a hardmount, write a large file over NFS, then remount using a softmount. This seems to clear it up. Remounting using NFSv1 as opposed to NFSv3 also fixes the issue, which makes me believe that asynchronous writes and cacheing are at the heart of the problem. We also confirmed that port scanning our Nortel switches lock them hard, too. --------------------------------------------------------------------------- ----------------------------------------------------------------------------
Current thread:
- Port scan causing system crashes steve . x . jones (Jun 12)
- Re: Port scan causing system crashes Helmut Springer (Jun 12)
- Re: Port scan causing system crashes Anthony Kim (Jun 12)
- Re: Port scan causing system crashes Adam Carter (Jun 13)
- <Possible follow-ups>
- RE: Port scan causing system crashes OBrien, Brennan (Jun 12)
- Re: Port scan causing system crashes MARTIN M. Bénoni (Jun 12)
- RE: Port scan causing system crashes Whiteside, Larry [contractor] (Jun 12)
- Re: Port scan causing system crashes Clem Skorupka (Jun 12)
- Re: Port scan causing system crashes Renaud Deraison (Jun 12)
- Re: Port scan causing system crashes Clem Skorupka (Jun 12)
- Re: Port scan causing system crashes Clem Skorupka (Jun 12)
- RE: Port scan causing system crashes Steve Goldsby (ICS) (Jun 12)
- Re: Port scan causing system crashes Death Star (Jun 12)
- RE: Port scan causing system crashes Brass, Phil (ISS Atlanta) (Jun 12)