Editing Transmission Control Protocol (section)

===Denial of service===
By using a [[IP address spoofing|spoofed IP address]] and repeatedly sending [[mangled packet|purposely assembled]] SYN packets, followed by many ACK packets, attackers can cause the server to consume large amounts of resources keeping track of the bogus connections. This is known as a [[SYN flood]] attack. Proposed solutions to this problem include [[SYN cookies]] and cryptographic puzzles, though SYN cookies come with their own set of vulnerabilities.<ref>{{Cite web |url=http://www.jakoblell.com/blog/2013/08/13/quick-blind-tcp-connection-spoofing-with-syn-cookies/ |title=Quick Blind TCP Connection Spoofing with SYN Cookies |author=Jakob Lell |date=13 August 2013 |access-date=2014-02-05 |archive-date=2014-02-22 |archive-url=https://web.archive.org/web/20140222101226/http://www.jakoblell.com/blog/2013/08/13/quick-blind-tcp-connection-spoofing-with-syn-cookies/ |url-status=live }}</ref> [[Sockstress]] is a similar attack, that might be mitigated with system resource management.<ref>{{cite web|url=http://www.gont.com.ar/talks/hacklu2009/fgont-hacklu2009-tcp-security.pdf|title=Some insights about the recent TCP DoS (Denial of Service) vulnerabilities|access-date=2010-12-23|archive-date=2013-06-18|archive-url=https://web.archive.org/web/20130618235445/http://www.gont.com.ar/talks/hacklu2009/fgont-hacklu2009-tcp-security.pdf|url-status=dead}}</ref> An advanced DoS attack involving the exploitation of the TCP ''persist timer'' was analyzed in [[Phrack]] No. 66.<ref>{{cite web|url=http://phrack.org/issues.html?issue=66&id=9#article|title=Exploiting TCP and the Persist Timer Infiniteness|access-date=2010-01-22|archive-date=2010-01-22|archive-url=https://web.archive.org/web/20100122131412/http://www.phrack.org/issues.html?issue=66&id=9#article|url-status=live}}</ref> [[PUSH and ACK floods]] are other variants.<ref>{{cite web|url=https://f5.com/glossary/push-and-ack-flood|title=PUSH and ACK Flood|website=f5.com|access-date=2017-09-27|archive-date=2017-09-28|archive-url=https://web.archive.org/web/20170928005428/https://f5.com/glossary/push-and-ack-flood|url-status=live}}</ref>