Editing FTP bounce attack

'''FTP bounce attack''' is an [[exploit (computer science)|exploit]] of the [[File Transfer Protocol|FTP]] protocol whereby an attacker is able to use the [[PORT command|PORT command]] to request access to [[Transmission Control Protocol|ports]] indirectly through the use of the victim machine, which serves as a proxy for the request, similar to an [[Open mail relay]] using [[SMTP]].<ref name="rfc2577">{{cite web
|url=https://tools.ietf.org/html/rfc2577
|title= RFC 2577
|author1=M. Allman |author2=S. Ostermann 
|date= 1999
|doi=10.17487/RFC2577
}} </ref>

This technique can be used to [[port scan]] hosts discreetly, and to potentially bypass a network's [[access-control list]] to access specific ports that the attacker cannot access through a direct connection, for example with the [[nmap]] [[port scanner]].<ref>[http://nmap.org/nsedoc/scripts/ftp-bounce.html "ftp-bounce"], Nmap Scripting Engine documentation</ref> 

Nearly all modern FTP server programs are configured by default to refuse [[File eXchange Protocol|{{mono|PORT}} commands that would connect to any host but the originating host]], thwarting FTP bounce attacks.

==See also==
* [[Confused deputy problem]]

==References==
{{reflist}}

==External links==
*[https://www.cert.org/historical/advisories/ca-1997-27.cfm CERT Advisory on FTP Bounce Attack]
*[https://web.archive.org/web/20131105191347/http://www.cert.org/tech_tips/ftp_port_attacks.html CERT Article on FTP Bounce Attack]
*[http://insecure.org/nmap/hobbit.ftpbounce.txt Original posting describing the attack]

[[Category:File Transfer Protocol]]
[[Category:Computer network security]]

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