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.
References
| Link | 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 |
| 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 |
Configurations
Configuration 1 (hide)
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Configuration 2 (hide)
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Configuration 3 (hide)
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Configuration 4 (hide)
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History
03 Jul 2025, 20:59
| Type | Values Removed | Values Added |
|---|---|---|
| CPE | cpe:2.3:a:owasp:modsecurity:*:*:*:*:*:*:*:* | |
| First Time |
Owasp
Owasp modsecurity |
21 Nov 2024, 06:28
| Type | Values Removed | Values Added |
|---|---|---|
| References | () https://lists.debian.org/debian-lts-announce/2022/05/msg00042.html - Mailing List, Third Party Advisory | |
| References | () https://www.debian.org/security/2021/dsa-5023 - Third Party Advisory | |
| References | () https://www.oracle.com/security-alerts/cpuapr2022.html - Patch, Third Party Advisory | |
| References | () https://www.trustwave.com/en-us/resources/blogs/spiderlabs-blog/modsecurity-dos-vulnerability-in-json-parsing-cve-2021-42717/ - Exploit, Mitigation, Vendor Advisory |
03 Sep 2022, 03:33
| Type | Values Removed | Values Added |
|---|---|---|
| References | (MLIST) https://lists.debian.org/debian-lts-announce/2022/05/msg00042.html - Mailing List, Third Party Advisory | |
| References | (MISC) https://www.oracle.com/security-alerts/cpuapr2022.html - Patch, Third Party Advisory | |
| CPE | cpe:2.3:a:oracle:http_server:12.2.1.4.0:*:*:*:*:*:*:* cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* cpe:2.3:a:oracle:http_server:12.2.1.3.0:*:*:*:*:*:*:* cpe:2.3:a:oracle:zfs_storage_appliance_kit:8.8:*:*:*:*:*:*:* |
02 Jun 2022, 14:15
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
20 Apr 2022, 00:16
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
05 Apr 2022, 21:00
| Type | Values Removed | Values Added |
|---|---|---|
| References | (DEBIAN) https://www.debian.org/security/2021/dsa-5023 - Third Party Advisory | |
| CPE | cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* |
19 Dec 2021, 11:15
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
10 Dec 2021, 01:36
| Type | Values Removed | Values Added |
|---|---|---|
| CVSS |
v2 : v3 : |
v2 : 5.0
v3 : 7.5 |
| References | (MISC) https://www.trustwave.com/en-us/resources/blogs/spiderlabs-blog/modsecurity-dos-vulnerability-in-json-parsing-cve-2021-42717/ - Exploit, Mitigation, Vendor Advisory | |
| CPE | cpe:2.3:a:trustwave:modsecurity:*:*:*:*:*:*:*:* cpe:2.3:a:f5:nginx_modsecurity_waf:r24:*:*:*:*:*:*:* cpe:2.3:a:f5:nginx_modsecurity_waf:r25:*:*:*:*:*:*:* |
|
| CWE | CWE-674 |
07 Dec 2021, 22:46
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2021-12-07 22:15
Updated : 2025-07-03 20:59
NVD link : CVE-2021-42717
Mitre link : CVE-2021-42717
CVE.ORG link : CVE-2021-42717
JSON object : View
Products Affected
f5
- nginx_modsecurity_waf
oracle
- zfs_storage_appliance_kit
- http_server
owasp
- modsecurity
debian
- debian_linux
trustwave
- modsecurity
CWE
CWE-674
Uncontrolled Recursion
