Unlike bandwidth-consumption DoS attacks, the "slow" attack does not require a large amount of traffic to be sent to the server - only that the client is able to maintain open connections for several minutes at a time. If the server maintains too many connections open at once, then it may not be able to respond to new, legitimate connections. This is an application-level DoS that consumes server resources by maintaining open connections for an extended period of time by slowly sending traffic to the server. The web application is possibly vulnerable to a "slow HTTP POST" Denial of Service (DoS) attack. ps I did not write this.īLACKLIST= cat /usr/local/AS/etc/blacklist.The customer has had the 2 items below reported on a penetration test of their API Gateway, could you confirm if there are any recommended fixes?
Slowloris attack mitigation code#
This code will stop other ddos attack methods as well. Apache tomcat team does not consider this a vulnerability in tomcat or plan to release a patch. This will not affect people using a proxy. An often-cited example is mod_php, though that may not apply to newer versions. In paritcular, it may not be compatible some older modules that rely on the thread-per-connection concept.
![slowloris attack mitigation slowloris attack mitigation](https://ars.els-cdn.com/content/image/1-s2.0-S1389128621003753-gr4.jpg)
![slowloris attack mitigation slowloris attack mitigation](https://www.researchgate.net/profile/Vigneshwaran-Selvaraj-2/publication/340929743/figure/fig19/AS:884417937543170@1587873076154/Global-slowloris-attack-statistics-map.png)
This is available on most modern installations, but is marked "expermental". Mod_reqtimeout works by limiting the amount of time a single request can stay idle.īoth have their place, and a good defense will probably employ both.Īlso, the mpm_event Apache worker configuration works the same way as other servers, such as Nginx, Cherokee, and lighttpd, and is not susceptible to the Slowloris attack. Mod_antiloris works by limiting the number of simultaneous connections a given IP can create. And there's also mod_reqtimeout, which depsite being part of Apache Core is often not included by default in Apache installations.
![slowloris attack mitigation slowloris attack mitigation](https://blog.mazebolt.com/hs-fs/hubfs/ddos_attack_OSI_layer_ddos_attack_type.jpg)
There's mod_antiloris, which will do that for you as described in the article you linked. If you use Apache in your solution, then you'll also need to use a slowloris mitigation stragegy. Set up Apache and Tomcat together as traditionally configured. Set up a reverse-proxy server in front of Tomcat, such as Nginx, Lighttpd, or even Apache. If Tomcat is directly exposed to the Internet (without being teamed up with Apache), then your solution should be one of the following: Tomcat typically doesn't run as a webserver, it runs as an application server. Below, "Apache" refers to the Apache HTTP Server, and not Tomcat. However, the traditional Apache webserver (officially called "The Apache HTTP Server Project") is frequently referred to simply as Apache. Note that Tomcat is part of the Apache Foundation, so technically it's called Apache Tomcat. Then use an Apache solution such as mod_reqtimeout or mod_antiloris. Unfortunately, the best option is to place the Tomcat service downstream from a web server that can better handle HTTP connections, such as Apache. mega-proxy), so the number of connections would need to be tuned reasonably - dependant on the traffic expected. This would, however, have side-effects if many users were legitimately connecting from a single IP (e.g. # iptables -A INPUT -p tcp -syn -dport 80 -m connlimit -connlimit-above 50 -j REJECT Of concurrent connections that can be established to port 80 from a single Here is an example of an iptables command which can be used to limit the number This will mitigate run-of-the-mill Denial of Service attacks but not distributed ones (DDoS).
![slowloris attack mitigation slowloris attack mitigation](https://i.imgur.com/69Jf1HW.png)
Use firewall rules to prevent too many connections from a single host. The Tomcat developers do not consider this to be a vulnerability, and have no plans to fix. More appropriate references there than the one you were given. A CVE has been assigned specifically for this issue as it applies to Apache Tomcat: CVE-2012-5568.