CVE-2018-1333 DoS for HTTP/2 connections by crafted requests

What is CVE-2018-1333?

CVE-2018-1333 is a high-severity denial of service vulnerability in Apache Http Server, published on 18 Jun 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

By specially crafting HTTP/2 requests, workers would be allocated 60 seconds longer than necessary, leading to worker exhaustion and a denial of service. Fixed in Apache HTTP Server 2.4.34 (Affected 2.4.18-2.4.30,2.4.33).

Weakness: CWE-400

Which versions are affected by CVE-2018-1333?

It affects 5 products.

Products include Apache Http Server, Canonical Ubuntu Linux, Netapp Cloud Backup, Netapp Storage Automation Store, Redhat Jboss Core Services.

How do I fix CVE-2018-1333?

Upgrade to a fixed version.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2018-1333 being exploited?

There is no known exploitation of CVE-2018-1333 in the wild and no public exploit code.

Other vulnerabilities in Apache Http Server

• CVE-2021-42013 Apache HTTP Server Path Traversal Exploited Critical 9.8
• CVE-2024-38475 Apache HTTP Server Improper Escaping of Output Exploited Critical 9.1
• CVE-2021-40438 Apache HTTP Server-Side Request Forgery (SSRF) Exploited Critical 9.0
• CVE-2019-0211 Apache HTTP Server Privilege Escalation Exploited High 7.8
• CVE-2021-41773 Apache HTTP Server Path Traversal Exploited High 7.5

All Apache Http Server vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as ALPINE-CVE-2018-1333, CLEANSTART-2026-MY08631, DEBIAN-CVE-2018-1333, GHSA-885g-r558-qx2m, SUSE-SU-2018:2336-1, UBUNTU-CVE-2018-1333.