CVE-2021-42717
Modsecurity 2 is similarly vulnerable: the affected versions include 2.8.0 through 2.9.4.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (3.15%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 3.15% probability · 87th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-674
- Affected
- owasp/modsecurity · trustwave/modsecurity · f5/nginx modsecurity waf · debian/debian linux · oracle/http server · oracle/zfs storage appliance kit
- Source
- cve@mitre.org
References
- https://lists.debian.org/debian-lts-announce/2022/05/msg00042.htmlMailing List, Third Party Advisory
- https://www.debian.org/security/2021/dsa-5023Third Party Advisory
- https://www.oracle.com/security-alerts/cpuapr2022.htmlPatch, 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.htmlMailing List, Third Party Advisory
- https://www.debian.org/security/2021/dsa-5023Third Party Advisory
- https://www.oracle.com/security-alerts/cpuapr2022.htmlPatch, 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
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.