CVE-2021-30639
Fixed upstream EPSS 7%
A vulnerability in Apache Tomcat allows an attacker to remotely trigger a denial of service. An error introduced as part of a change to improve error handling during non-blocking I/O meant that the error flag associated with the Request object was not reset between requests. This meant that once a non-blocking I/O error occurred, all future requests handled by that request object would fail. Users were able to trigger non-blocking I/O errors, e.g. by dropping a connection, thereby creating the possibility of triggering a DoS. Applications that do not use non-blocking I/O are not exposed to this vulnerability. This issue affects Apache Tomcat 10.0.3 to 10.0.4; 9.0.44; 8.5.64.
Products: Apache Software Foundation Apache Tomcat
Fixed upstream
| Ecosystem | Package | Fixed in |
|---|---|---|
| Maven | org.apache.tomcat:tomcat | 10.0.5 |
| Maven | org.apache.tomcat:tomcat | 9.0.45 |
| Maven | org.apache.tomcat:tomcat | 8.5.65 |
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| Ubuntu 22.04 LTS | tomcat9 | no fix |
| Ubuntu 24.04 LTS | tomcat9 | no fix |
| Ubuntu 25.04 | tomcat9 | no fix |
| Ubuntu Pro 14.04 LTS | tomcat6 | no fix |
| Ubuntu Pro 14.04 LTS | tomcat7 | no fix |
| Ubuntu Pro 16.04 LTS | tomcat6 | no fix |
| Ubuntu Pro 16.04 LTS | tomcat7 | no fix |
| Ubuntu Pro 16.04 LTS | tomcat8 | no fix |
| Ubuntu Pro 18.04 LTS | tomcat7 | no fix |
| Ubuntu Pro 18.04 LTS | tomcat8 | no fix |
| Ubuntu Pro 18.04 LTS | tomcat9 | no fix |
| Ubuntu Pro 20.04 LTS | tomcat9 | no fix |