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UBUNTU-CVE-2021-30639 (CVE-2021-30639)

Vulnerability from osv_ubuntu – Published: 2021-07-12 15:15 – Updated: 2025-07-14 04:36 – Source website
Withdrawn 2025-08-21 VLAI
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.

Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
N/A (UNKNOWN)
medium
References
To clipboard 

{
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        "name": "tomcat6",
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    {
      "ecosystem_specific": {},
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      },
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        "9.0.70-2ubuntu1.25.04.2"
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    }
  ],
  "aliases": [],
  "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.",
  "id": "UBUNTU-CVE-2021-30639",
  "modified": "2025-07-14T04:36:57Z",
  "published": "2021-07-12T15:15:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2021-30639"
    },
    {
      "type": "REPORT",
      "url": "https://bz.apache.org/bugzilla/show_bug.cgi?id=65203"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/apache/tomcat/commit/8ece47c4a9fb9349e8862c84358a4dd23c643a24"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/apache/tomcat/commit/411caf29ac1c16e6ac291b6e5543b2371dbd25e2"
    },
    {
      "type": "REPORT",
      "url": "https://lists.apache.org/thread.html/rd84fae1f474597bdf358f5bdc0a5c453c507bd527b83e8be6b5ea3f4%40%3Cannounce.tomcat.apache.org%3E"
    },
    {
      "type": "REPORT",
      "url": "https://lists.apache.org/thread.html/r79a7c019712b39aedf7cf4da9276d80610f04441b2a4f6506cb2daaf@%3Cusers.tomcat.apache.org%3E"
    },
    {
      "type": "REPORT",
      "url": "https://lists.apache.org/thread.html/r79a7c019712b39aedf7cf4da9276d80610f04441b2a4f6506cb2daaf@%3Cdev.tomcat.apache.org%3E"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2021-30639"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2021-30639"
  ],
  "withdrawn": "2025-08-21T16:42:12Z"
}



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  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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