CVE-2021-42717

Publication date 7 December 2021

Last updated 24 July 2024

Ubuntu priority

Cvss 3 Severity Score

ModSecurity 3.x through 3.0.5 mishandles excessively nested JSON objects. Crafted JSON objects with nesting tens-of-thousands deep could result in the web server being unable to service legitimate requests. Even a moderately large (e.g., 300KB) HTTP request can occupy one of the limited NGINX worker processes for minutes and consume almost all of the available CPU on the machine. Modsecurity 2 is similarly vulnerable: the affected versions include 2.8.0 through 2.9.4.

Status

Show unmaintained releases

Package	Ubuntu Release	Status
modsecurity	24.04 LTS noble	Needs evaluation
	23.10 mantic	Ignored
	23.04 lunar	Ignored
	22.10 kinetic	Ignored
	22.04 LTS jammy	Needs evaluation
	21.10 impish	Ignored
	21.04 hirsute	Ignored
	20.04 LTS focal	Needs evaluation
	16.04 LTS xenial	Ignored
	14.04 LTS trusty	Ignored
modsecurity-apache	24.04 LTS noble	Not affected
	23.10 mantic	Not affected
	23.04 lunar	Not affected
	22.10 kinetic	Ignored
	22.04 LTS jammy	Not affected
	21.10 impish	Ignored
	21.04 hirsute	Ignored
	20.04 LTS focal	Fixed 2.9.3-1ubuntu0.1
	18.04 LTS bionic	Fixed 2.9.2-1ubuntu0.1~esm1 Ubuntu Pro
	16.04 LTS xenial	Fixed 2.9.0-1ubuntu0.1~esm1 Ubuntu Pro
	14.04 LTS trusty	Not affected

Get expanded security coverage with Ubuntu Pro

Reduce your average CVE exposure time from 98 days to 1 day with expanded CVE patching, ten-years security maintenance and optional support for the full stack of open-source applications. Free for personal use.

Get Ubuntu Pro

Severity score breakdown

Parameter	Value
Base score	7.5 · High
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

Related Ubuntu Security Notices (USN)

USN-6370-1
ModSecurity vulnerabilities
14 September 2023