From 9f76eade3dd69e44d67b98128d389422a36e6c98 Mon Sep 17 00:00:00 2001
From: Ruediger Pluem
Date: Tue, 17 Jan 2006 19:58:19 +0000
Subject: [PATCH] * Add a sentence about DDOS. * Mention problems with low
Timeouts and long running CGIs. * Stress out the experimental character of
event MPM and that it does not work with ssl currently.
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@369902 13f79535-47bb-0310-9956-ffa450edef68
---
docs/manual/misc/security_tips.xml | 28 +++++++++++++++++++++-------
1 file changed, 21 insertions(+), 7 deletions(-)
diff --git a/docs/manual/misc/security_tips.xml b/docs/manual/misc/security_tips.xml
index 72a82000259..2d3fb80ed65 100644
--- a/docs/manual/misc/security_tips.xml
+++ b/docs/manual/misc/security_tips.xml
@@ -66,7 +66,8 @@
other operating-system configurations. For example, most
firewalls can be configured to restrict the number of simultaneous
connections from any individual IP address or network, thus
- preventing a range of simple attacks.
+ preventing a range of simple attacks. Of course this is no help
+ against Distributed Denial of Service attacks (DDoS).
There are also certain Apache HTTP Server configuration
settings that can help mitigate problems:
@@ -74,10 +75,19 @@
- The TimeOut directive
should be lowered on sites that are subject to DoS attacks.
- Setting this to as low as a few seconds may be appropriate. See
- also the KeepAliveTimeout
- directive and various timeout-related directives provided by
- different modules.
+ Setting this to as low as a few seconds may be appropriate.
+ As TimeOut is currently
+ used for several different operations, setting it to a low value
+ introduces problems with long running CGI scripts.
+
+ - The KeepAliveTimeout
+ directive may be also lowered on sites that are subject to DoS
+ attacks. Some sites even turn off the keepalives completely via
+ KeepAlive, which has of course
+ other drawbacks on performance.
+
+ - The values of various timeout-related directives provided by
+ other modules should be checked.
- The directives
LimitRequestBody,
@@ -103,9 +113,13 @@
- The use of a threaded mpm may
allow you to handle more simultaneous connections, thereby
- mitigating DoS attacks. Further, the event mpm
+ mitigating DoS attacks. Further, the experimental
+ event mpm
uses asynchronous processing to avoid devoting a thread to each
- connection.
+ connection. At the current point of time this
+ is work in progress and not fully implemented. Especially the
+ event mpm is currently incompatible with
+ mod_ssl and other input filters.
- There are a number of third-party modules available through