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 |