Vulnerability 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.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Owasp | Modsecurity | >= 3.0.0, < 3.0.6 |
| Trustwave | Modsecurity | >= 2.0.0, < 2.9.5 |
| F5 | Nginx Modsecurity Waf | r24 |
| Debian | Debian Linux | 9.0 |
| Oracle | Http Server | 12.2.1.3.0 |
| Oracle | Zfs Storage Appliance Kit | 8.8 |
Related Weaknesses (CWE)
References
- https://lists.debian.org/debian-lts-announce/2022/05/msg00042.htmlMailing ListThird Party Advisory
- https://www.debian.org/security/2021/dsa-5023Third Party Advisory
- https://www.oracle.com/security-alerts/cpuapr2022.htmlPatchThird Party Advisory
- https://www.trustwave.com/en-us/resources/blogs/spiderlabs-blog/modsecurity-dos-ExploitMitigationVendor Advisory
- https://lists.debian.org/debian-lts-announce/2022/05/msg00042.htmlMailing ListThird Party Advisory
- https://www.debian.org/security/2021/dsa-5023Third Party Advisory
- https://www.oracle.com/security-alerts/cpuapr2022.htmlPatchThird Party Advisory
- https://www.trustwave.com/en-us/resources/blogs/spiderlabs-blog/modsecurity-dos-ExploitMitigationVendor Advisory
FAQ
What is CVE-2021-42717?
CVE-2021-42717 is a vulnerability with a CVSS score of 7.5 (HIGH). 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 req...
How severe is CVE-2021-42717?
CVE-2021-42717 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2021-42717?
Check the references section above for vendor advisories and patch information. Affected products include: Owasp Modsecurity, Trustwave Modsecurity, F5 Nginx Modsecurity Waf, Debian Debian Linux, Oracle Http Server.