Vulnerability in F5 Nginx_modsecurity_waf

CVE-2021-42717

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., 3…

EPSS: 0.032 (86.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

  • cve@mitre.org (vendor-advisory, Third Party Advisory, x_refsource_DEBIAN)
  • cve@mitre.org (Patch, Third Party Advisory, x_refsource_MISC)
  • cve@mitre.org (Exploit, x_refsource_MISC, Mitigation, Vendor Advisory)
  • cve@mitre.org (mailing-list, x_refsource_MLIST, Mailing List, Third Party Advisory)

Frequently asked questions

What is CVE-2021-42717?
CVE-2021-42717 is a high-severity vulnerability in F5 Nginx_modsecurity_waf, classified under Uncontrolled Recursion. CVSS score: 7.5/10. Published 2021-12-07.
How severe is CVE-2021-42717?
High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2021-42717 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.