| Name |
HTTP Flood |
|
| Likelyhood of attack |
Typical severity |
| Low |
High |
|
| Summary |
An adversary may execute a flooding attack using the HTTP protocol with the intent to deny legitimate users access to a service by consuming resources at the application layer such as web services and their infrastructure. These attacks use legitimate session-based HTTP GET requests designed to consume large amounts of a server's resources. Since these are legitimate sessions this attack is very difficult to detect. |
| Prerequisites |
This type of an attack requires the ability to generate a large amount of HTTP traffic to send to a target server. |
| Solutions | Design: Use a Web Application Firewall (WAF) to help filter out malicious traffic. This can be setup with rules to block IP addresses found in IP reputation databases, which contains lists of known bad IP addresses. Analysts should also monitor when the traffic flow becomes abnormally large, and be able to add on-the-fly rules to block malicious traffic. Special care should be taken to ensure low false positive rates in block rules and functionality should be implemented to allow a legitimate user to resume sending traffic if they have been blocked. Hire a third party provider to implement a Web Application Firewall (WAF) for your application. Third party providers have dedicated resources and expertise that could allow them to update rules and prevent HTTP Floods very quickly. Design: Use a load balancer such as nginx to prevent small scale HTTP Floods by dispersing traffic between a group of servers. Implementation: Make a requesting machine solve some kind of challenge before allowing them to send an HTTP request. This could be a captcha or something similar that works to deter bots. |
| Related Weaknesses |
|
CWE ID
|
Description
|
| CWE-770 |
Allocation of Resources Without Limits or Throttling |
|
| Related CAPECS |
|
CAPEC ID
|
Description
|
| CAPEC-125 |
An adversary consumes the resources of a target by rapidly engaging in a large number of interactions with the target. This type of attack generally exposes a weakness in rate limiting or flow. When successful this attack prevents legitimate users from accessing the service and can cause the target to crash. This attack differs from resource depletion through leaks or allocations in that the latter attacks do not rely on the volume of requests made to the target but instead focus on manipulation of the target's operations. The key factor in a flooding attack is the number of requests the adversary can make in a given period of time. The greater this number, the more likely an attack is to succeed against a given target. |
|
| Taxonomy: ATTACK |
|
Entry ID
|
Entry Name
|
| 1499.002 |
Endpoint Denial of Service:Service Exhaustion Flood |
|