{"id":"BIT-tomcat-2021-30639","summary":"DoS after non-blocking IO error","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.","aliases":["CVE-2021-30639","GHSA-44qp-qhfv-c7f6"],"modified":"2026-09-08T08:48:20.858738938Z","published":"2024-03-06T11:10:12.195Z","database_specific":{"severity":"High","cpes":["cpe:2.3:a:apache:tomcat:10.0.3:*:*:*:*:*:*:*","cpe:2.3:a:apache:tomcat:10.0.4:*:*:*:*:*:*:*","cpe:2.3:a:apache:tomcat:8.5.64:*:*:*:*:*:*:*","cpe:2.3:a:apache:tomcat:9.0.44:*:*:*:*:*:*:*","cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*"]},"references":[{"type":"ADVISORY","url":"https://kc.mcafee.com/corporate/index?page=content&id=SB10366"},{"type":"WEB","url":"https://lists.apache.org/thread.html/r79a7c019712b39aedf7cf4da9276d80610f04441b2a4f6506cb2daaf%40%3Cdev.tomcat.apache.org%3E"},{"type":"WEB","url":"https://lists.apache.org/thread.html/r79a7c019712b39aedf7cf4da9276d80610f04441b2a4f6506cb2daaf%40%3Cusers.tomcat.apache.org%3E"},{"type":"ADVISORY","url":"https://lists.apache.org/thread.html/rd84fae1f474597bdf358f5bdc0a5c453c507bd527b83e8be6b5ea3f4%40%3Cannounce.tomcat.apache.org%3E"},{"type":"ADVISORY","url":"https://security.gentoo.org/glsa/202208-34"},{"type":"ADVISORY","url":"https://security.netapp.com/advisory/ntap-20210827-0007/"},{"type":"ADVISORY","url":"https://www.oracle.com/security-alerts/cpujan2022.html"},{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-30639"}],"affected":[{"package":{"name":"tomcat","ecosystem":"Bitnami","purl":"pkg:bitnami/tomcat"},"ranges":[{"type":"SEMVER","events":[{"introduced":"8.5.64"},{"fixed":"8.5.65"},{"introduced":"9.0.44"},{"fixed":"9.0.45"},{"introduced":"10.0.3"},{"fixed":"10.0.4"},{"introduced":"10.0.4"},{"fixed":"10.0.5"}]}],"database_specific":{"source":"https://github.com/bitnami/vulndb/tree/main/data/tomcat/BIT-tomcat-2021-30639.json"},"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}],"schema_version":"1.9.0"}