CVE-2021-42717
Published: 7 December 2021
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.
Priority
Status
Package | Release | Status |
---|---|---|
modsecurity Launchpad, Ubuntu, Debian |
lunar |
Needs triage
|
focal |
Needs triage
|
|
trusty |
Ignored
(end of standard support)
|
|
upstream |
Needs triage
|
|
xenial |
Ignored
(end of standard support)
|
|
hirsute |
Ignored
(end of life)
|
|
impish |
Ignored
(end of life)
|
|
jammy |
Needs triage
|
|
kinetic |
Ignored
(end of life, was needs-triage)
|
|
mantic |
Needs triage
|
|
modsecurity-apache Launchpad, Ubuntu, Debian |
lunar |
Not vulnerable
(2.9.7-1)
|
bionic |
Released
(2.9.2-1ubuntu0.1~esm1)
Available with Ubuntu Pro |
|
focal |
Released
(2.9.3-1ubuntu0.1)
|
|
xenial |
Released
(2.9.0-1ubuntu0.1~esm1)
Available with Ubuntu Pro |
|
hirsute |
Ignored
(end of life)
|
|
impish |
Ignored
(end of life)
|
|
kinetic |
Ignored
(end of life, was needs-triage)
|
|
jammy |
Not vulnerable
(2.9.5-1)
|
|
trusty |
Not vulnerable
(code not present)
|
|
upstream |
Released
(2.9.7-1)
|
|
mantic |
Not vulnerable
(2.9.7-1)
|
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 |