UBUNTU-CVE-2021-30639

Dashboard / Vulnerabilities / UBUNTU-CVE-2021-30639

UBUNTU-CVE-2021-30639

Summary:

Details: 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.

References: https://ubuntu.com/security/CVE-2021-30639, https://bz.apache.org/bugzilla/show_bug.cgi?id=65203, https://github.com/apache/tomcat/commit/8ece47c4a9fb9349e8862c84358a4dd23c643a24, https://github.com/apache/tomcat/commit/411caf29ac1c16e6ac291b6e5543b2371dbd25e2, https://lists.apache.org/thread.html/rd84fae1f474597bdf358f5bdc0a5c453c507bd527b83e8be6b5ea3f4%40%3Cannounce.tomcat.apache.org%3E, https://lists.apache.org/thread.html/r79a7c019712b39aedf7cf4da9276d80610f04441b2a4f6506cb2daaf@%3Cusers.tomcat.apache.org%3E, https://lists.apache.org/thread.html/r79a7c019712b39aedf7cf4da9276d80610f04441b2a4f6506cb2daaf@%3Cdev.tomcat.apache.org%3E, https://www.cve.org/CVERecord?id=CVE-2021-30639