slowhttptest1

Denial of service attacks simulator

Usage

slowhttptest [{-H | B | R | X}] [-g] [-a range start] [-b range limit] [-c number of connections] [-d all traffic directed through HTTP proxy at host:port] [-e probe traffic directed through HTTP proxy at host:port] [-f value of Content-type header] [-i interval in seconds] [-k request multiply factor] [-l test duration in seconds] [-m value of Accept header] [-n slow read interval in seconds] [-o output file path and/or name] [-p timeout for probe connection in seconds] [-r connection per second] [-s value of Content-Length header] [-t HTTP verb] [-1 HTTP header] [-u absolute URL] [-v output verbosity level] [-w advertised window size range start] [-x max length of follow up data] [-y advertised window size range end] [-z slow read from receive buffer in bytes]

Overview

The slowhttptest implements most common low-bandwidth Application Layer DoS attacks and produces CSV and HTML files with test statistics.

Currently supported attacks are:

Slowloris
Slow HTTP POST
Apache Range Header
Slow Read

The options are as follows:

-g: Forces slowhttptest to generate CSV and HTML files when test finishes with timestamp in filename.
-H: Starts slowhttptest in SlowLoris mode, sending unfinished HTTP requests.
-B: Starts slowhttptest in Slow POST mode, sending unfinished HTTP message bodies.
-R: Starts slowhttptest in Range Header mode, sending malicious Range Request header data.
-X: Starts slowhttptest in Slow Read mode, reading HTTP responses slowly.
-a start: Sets the start value of range-specifier for Range Header attack.
-b bytes: Sets the limit value of range-specifier for Range Header attack.
-c number of connections: Specifies the target number of connections to establish during the test.
-d HTTP proxy host:port: Specifies HTTP proxy server to connect to for all connections.
-e HTTP proxy host:port: Specifies HTTP proxy server to connect to for probe connections.
-f content-type: Specifies the value of Content-Type header.
-i seconds: Specifies the interval between follow up data for slowrois and Slow POST tests.
-k pipeline factor: Specifies number of times the resource would be requested per socket in Slow Read test.
-l seconds: Specifies test duration in seconds.
-m accept: Specifies the value of Accept header.
-n seconds: Specifies the interval between read operations for Slow Read test.
-o file name: Specifies custom file name, effective with -g.
-p seconds: Specifies the interval to wait for HTTP response on probe connection, before marking the server as DoSed.
-r connections per second: Specifies the connection rate.
-s bytes: Specifies the value of Content-Length header for Slow POST test.
-t HTTP verb: Specifies the verb to use in HTTP request.
-1 header: Specifies an HTTP header to use in HTTP request.
-u URL: Specifies the URL.
-v level: Specifies the verbosity level of logging.
-w bytes: Specifies the start of the range the TCP advertised window size would be picked from in Slow Read test.
-x bytes: Specifies the maximum length of follow up data for slowloris and Slow POST tests.
-y bytes: Specifies the end of the range the TCP advertised window size would be picked from in Slow Read test.
-z bytes: Specifies the number of bytes to read from receive buffer with each read() operation.

Environment

SSL_CERT: Specifies client certificate (PEM format)
SSL_KEY: Specifies client private key (PEM format)

Examples

Start a slowloris test of host.example.com with 1000 connections, statistics goes into my_header_stats, interval between follow up headers is 10 seconds and connection rate is 200 connections per second:

$ slowhttptest -c 1000 -H -g -o my_header_stats -i 10 -r 200 -t GET -u https://host.example.com/index.html -x 24 -p 3

Start slow POST test of host.example.com with 3000 connections, statistics goes into my_body_stats, interval between follow up headers is 110 seconds, connection rate is 200 connections per second, Content-Length header value is 8192, maximum length of follow up data is random value limited by 10 bytes and probe connections waits 3 seconds for HTTP response before marking server as DoSed:

$ slowhttptest -c 3000 -B -g -o my_body_stats -i 110 -r 200 -s 8192 -t FAKEVERB -u http://host.example.com/loginform.html -x 10 -p 3

Start Range Header test of host.example.com with 1000 connections, use HEAD verb, and generate HTTP header Range:0-, x-1, x-2, x-3, ... x-y, where x is 10 and y is 3000, connection rate is 500: interval between follow up headers is 10 seconds and connection rate is 200 connections per second:

$ slowhttptest -R -u http://host.example.com/ -t HEAD -c 1000 -a 10 -b 3000 -r 500

Start Slow Read test of host.example.com with 8000 connections, no statistics is generated, connection rate is 200 connections per second, TCP advertised window size is a random value between 512 and 1024, slowhttptest reads 32 bytes from each connections every 5 seconds, 3 requests are pipelined per each connections, probe connection waits 3 seconds for HTTP response before marking server as DoSed:

$ slowhttptest -c 8000 -X -r 200 -w 512 -y 1024 -n 5 -z 32 -k 3 -u https://host.example.com/resources/index.html -p 3

Start Slow Read test of host.example.com through HTTP proxy server at 10.10.0.1:8080 with 8000 connections, no statistics is generated, the rest test values are default. slowhttptest most likely would test HTTP proxy server itself, rather than target server, but it all depends on the HTTP proxy server implementation:

$ slowhttptest -d 10.10.0.1:8080 -c 8000 -X -u https://host.example.com/resources/index.html

Start Slow Read test of host.example.com and direct probe traffic through HTTP proxy server at 10.10.0.1:8080 with 8000 connections, no statistics is generated, the rest test values are default. Specifying another connection channel for probe connections helps to make sure that slowhttptest shows valid statistics for availability of server under test:

$ slowhttptest -e 10.10.0.1:8080 -c 8000 -X -u https://host.example.com/resources/index.html

History

Arch Linux 2026-11-01: the text shown here
Debian 13 (Trixie) to Debian 9 (Stretch)
Debian 8 (Jessie)

-1 since Arch Linux 2026-11-01; -f since Debian 9 (Stretch); -m since Debian 9 (Stretch).