CVE-2021-42717
Apache ModSecurity NGINX Nested JSON Object Denial of Service (DoS)
Description
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.
INFO
Published Date :
Dec. 7, 2021, 10:15 p.m.
Last Modified :
Sept. 3, 2022, 3:33 a.m.
Source :
[email protected]
Remotely Exploitable :
Yes !
Impact Score :
3.6
Exploitability Score :
3.9
Public PoC/Exploit Available at Github
CVE-2021-42717 has a 1 public PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
Affected Products
The following products are affected by CVE-2021-42717
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2021-42717.
| URL | Resource |
|---|---|
| https://lists.debian.org/debian-lts-announce/2022/05/msg00042.html | Mailing List Third Party Advisory |
| https://www.debian.org/security/2021/dsa-5023 | Third Party Advisory |
| https://www.oracle.com/security-alerts/cpuapr2022.html | Patch Third Party Advisory |
| https://www.trustwave.com/en-us/resources/blogs/spiderlabs-blog/modsecurity-dos-vulnerability-in-json-parsing-cve-2021-42717/ | Exploit Mitigation Vendor Advisory |
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Detection and Mitigation script for CVE-2021-42717 -> ModSecurity DoS Vulnerability in JSON Parsing
Shell
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2021-42717 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2021-42717 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by [email protected]
May. 14, 2024
Action Type Old Value New Value -
Modified Analysis by [email protected]
Sep. 03, 2022
Action Type Old Value New Value Changed Reference Type https://lists.debian.org/debian-lts-announce/2022/05/msg00042.html No Types Assigned https://lists.debian.org/debian-lts-announce/2022/05/msg00042.html Mailing List, Third Party Advisory Changed Reference Type https://www.oracle.com/security-alerts/cpuapr2022.html No Types Assigned https://www.oracle.com/security-alerts/cpuapr2022.html Patch, Third Party Advisory Changed CPE Configuration OR *cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* *cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* OR *cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* *cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* *cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* Added CPE Configuration OR *cpe:2.3:a:oracle:http_server:12.2.1.3.0:*:*:*:*:*:*:* *cpe:2.3:a:oracle:http_server:12.2.1.4.0:*:*:*:*:*:*:* *cpe:2.3:a:oracle:zfs_storage_appliance_kit:8.8:*:*:*:*:*:*:* -
CVE Modified by [email protected]
Jun. 02, 2022
Action Type Old Value New Value Added Reference https://lists.debian.org/debian-lts-announce/2022/05/msg00042.html [No Types Assigned] -
CVE Modified by [email protected]
Apr. 20, 2022
Action Type Old Value New Value Added Reference https://www.oracle.com/security-alerts/cpuapr2022.html [No Types Assigned] -
Modified Analysis by [email protected]
Apr. 05, 2022
Action Type Old Value New Value Changed Reference Type https://www.debian.org/security/2021/dsa-5023 No Types Assigned https://www.debian.org/security/2021/dsa-5023 Third Party Advisory Added CPE Configuration OR *cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* *cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* -
CVE Modified by [email protected]
Dec. 19, 2021
Action Type Old Value New Value Added Reference https://www.debian.org/security/2021/dsa-5023 [No Types Assigned] -
Initial Analysis by [email protected]
Dec. 10, 2021
Action Type Old Value New Value Added CVSS V2 NIST (AV:N/AC:L/Au:N/C:N/I:N/A:P) Added CVSS V3.1 NIST AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Changed Reference Type https://www.trustwave.com/en-us/resources/blogs/spiderlabs-blog/modsecurity-dos-vulnerability-in-json-parsing-cve-2021-42717/ No Types Assigned https://www.trustwave.com/en-us/resources/blogs/spiderlabs-blog/modsecurity-dos-vulnerability-in-json-parsing-cve-2021-42717/ Exploit, Mitigation, Vendor Advisory Added CWE NIST CWE-674 Added CPE Configuration OR *cpe:2.3:a:trustwave:modsecurity:*:*:*:*:*:*:*:* versions from (including) 2.0.0 up to (excluding) 2.9.5 *cpe:2.3:a:trustwave:modsecurity:*:*:*:*:*:*:*:* versions from (including) 3.0.0 up to (excluding) 3.0.6 Added CPE Configuration OR *cpe:2.3:a:f5:nginx_modsecurity_waf:r24:*:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_modsecurity_waf:r25:*:*:*:*:*:*:*
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-42717 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2021-42717
weaknesses.
Exploit Prediction
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.
0.60 }} 0.18%
score
0.78872
percentile