CVE-2021-30639

Published: 12 July 2021

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.

Priority

Cvss 3 Severity Score

7.5

Score breakdown

Status

Package	Release	Status
tomcat6 Launchpad, Ubuntu, Debian	bionic	Does not exist
	focal	Does not exist
	groovy	Does not exist
	hirsute	Does not exist
	impish	Does not exist
	jammy	Does not exist
	kinetic	Does not exist
	lunar	Does not exist
	mantic	Does not exist
	trusty	Needs triage
	upstream	Needs triage
	xenial	Needs triage
tomcat7 Launchpad, Ubuntu, Debian	bionic	Needs triage
	focal	Does not exist
	groovy	Does not exist
	hirsute	Does not exist
	impish	Does not exist
	jammy	Does not exist
	kinetic	Does not exist
	lunar	Does not exist
	mantic	Does not exist
	trusty	Needs triage
	upstream	Needs triage
	xenial	Needs triage
tomcat8 Launchpad, Ubuntu, Debian	bionic	Needs triage
	focal	Does not exist
	groovy	Does not exist
	hirsute	Does not exist
	impish	Does not exist
	jammy	Does not exist
	kinetic	Does not exist
	lunar	Does not exist
	mantic	Does not exist
	trusty	Does not exist
	upstream	Needs triage
	xenial	Needs triage
tomcat9 Launchpad, Ubuntu, Debian	bionic	Needs triage
	focal	Needs triage
	groovy	Ignored (end of life)
	hirsute	Ignored (end of life)
	impish	Ignored (end of life)
	jammy	Needs triage
	kinetic	Ignored (end of life, was needs-triage)
	lunar	Ignored (end of life, was needs-triage)
	mantic	Needs triage
	trusty	Does not exist
	upstream	Needs triage
	xenial	Does not exist

Severity score breakdown

Parameter	Value
Base score	7.5
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality	None
Integrity impact	None
Availability impact	High
Vector	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

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