CVE-2021-28165 Jetty vulnerable to incorrect handling of invalid large TLS frame, exhausting CPU resources
Attackers can cause 100% CPU usage and service disruption in Eclipse Jetty by sending large invalid TLS frames.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-28165?
CVE-2021-28165 is a high-severity denial of service vulnerability in Eclipse Jetty, published on 1 Apr 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In Eclipse Jetty 7.2.2 to 9.4.38, 10.0.0.alpha0 to 10.0.1, and 11.0.0.alpha0 to 11.0.1, CPU usage can reach 100% upon receiving a large invalid TLS frame.
Which versions are affected by CVE-2021-28165?
7 open source packages ship an affected version, including org.eclipse.jetty:jetty-server and jenkins. It affects 21 products.
| Package | Affected | Fixed in |
|---|---|---|
org.eclipse.jetty:jetty-server Maven | From 10.0.0 | 10.0.2 |
org.eclipse.jetty:jetty-server Maven | From 10.0.0 | 10.0.2 |
org.eclipse.jetty:jetty-server Maven | From 11.0.0 | 11.0.2 |
org.eclipse.jetty:jetty-server Maven | From 11.0.0 | 11.0.2 |
org.eclipse.jetty:jetty-server Maven | From 7.2.2 | 9.4.39 |
org.eclipse.jetty:jetty-server Maven | From 7.2.2 | 9.4.39 |
1 more packages
jenkins Bitnami | All versions | 2.286.0 |
Products include Eclipse Jetty, Jenkins Jenkins, Netapp Cloud Manager, Netapp E-Series Performance Analyzer, Netapp E-Series Santricity Os Controller, Netapp E-Series Santricity Storage and 15 more.
How do I fix CVE-2021-28165?
Upgrade org.eclipse.jetty:jetty-server to a fixed version for your release line: 10.0.2, 11.0.2 or 9.4.39.
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-2021-28165 being exploited?
There is no known exploitation of CVE-2021-28165 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Other vulnerabilities in Eclipse Jetty
- CVE-2016-4800 Jetty contains an alias issue that could allow unauthenticated remote code execution due to specially crafted request
- CVE-2019-17638 Operation on a Resource after Expiration or Release in Jetty Server
- CVE-2018-12538 Access and integrity issue within Eclipse Jetty
- CVE-2026-10050 Digest authentication lossy encoding
- CVE-2025-5115 MadeYouReset HTTP/2 vulnerability
Sources
Also known as BIT-jenkins-2021-28165, CLEANSTART-2026-BW99256, DEBIAN-CVE-2021-28165, GHSA-26vr-8j45-3r4w, UBUNTU-CVE-2021-28165.