CVE-2018-17189 : Exploit Details and Defense Strategies
Learn about CVE-2018-17189 affecting Apache HTTP Server versions 2.4.17 to 2.4.37. This vulnerability allowed for a DoS attack via slow request bodies in HTTP/2 connections. Find out how to mitigate and prevent this security issue.
CVE-2018-17189 was published on January 22, 2019, affecting Apache HTTP Server versions 2.4.17 to 2.4.37. The vulnerability allowed for a Denial of Service (DoS) attack via slow request bodies in HTTP/2 connections.
Understanding CVE-2018-17189
This CVE entry pertains to a specific issue in Apache HTTP Server versions 2.4.37 and earlier that could be exploited to impact server performance.
What is CVE-2018-17189?
The vulnerability in Apache HTTP Server versions 2.4.37 and prior allowed attackers to occupy server threads unnecessarily by sending request bodies in a slow loris manner to plain resources, affecting HTTP/2 connections.
The Impact of CVE-2018-17189
The vulnerability impacted the h2 stream for requests, causing server threads to be tied up cleaning up incoming data when slow request bodies were sent in a specific manner.
Technical Details of CVE-2018-17189
CVE-2018-17189 involved a specific issue related to the handling of request bodies in a slow loris manner in Apache HTTP Server versions 2.4.37 and earlier.
Vulnerability Description
The h2 stream for a request in affected versions of Apache HTTP Server occupied a server thread unnecessarily when slow request bodies were sent, impacting HTTP/2 connections.
Affected Systems and Versions
- Product: Apache HTTP Server
- Vendor: Apache Software Foundation
- Versions: 2.4.17 to 2.4.37
Exploitation Mechanism
Attackers could exploit this vulnerability by sending request bodies in a slow loris manner to plain resources, specifically impacting connections using HTTP/2 (mod_http2).
Mitigation and Prevention
To address CVE-2018-17189, consider the following steps:
Immediate Steps to Take
- Update Apache HTTP Server to a non-vulnerable version.
- Monitor server performance for any unusual activity.
Long-Term Security Practices
- Regularly update and patch software to mitigate known vulnerabilities.
- Implement network-level protections to detect and block DoS attacks.
Patching and Updates
- Apply patches provided by Apache Software Foundation to fix the vulnerability and enhance server security.