{"id":"BIT-modsecurity-2021-42717","details":"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.","aliases":["BIT-modsecurity2-2021-42717","CVE-2021-42717"],"modified":"2025-07-04T08:10:20.098Z","published":"2024-03-06T10:57:07.180Z","database_specific":{"severity":"High","cpes":["cpe:2.3:a:trustwave:modsecurity:*:*:*:*:*:*:*:*"]},"references":[{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2022/05/msg00042.html"},{"type":"WEB","url":"https://www.debian.org/security/2021/dsa-5023"},{"type":"WEB","url":"https://www.oracle.com/security-alerts/cpuapr2022.html"},{"type":"WEB","url":"https://www.trustwave.com/en-us/resources/blogs/spiderlabs-blog/modsecurity-dos-vulnerability-in-json-parsing-cve-2021-42717/"},{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-42717"}],"affected":[{"package":{"name":"modsecurity","ecosystem":"Bitnami","purl":"pkg:bitnami/modsecurity"},"ranges":[{"type":"SEMVER","events":[{"introduced":"2.0.0"},{"fixed":"2.9.5"}]}],"database_specific":{"source":"https://github.com/bitnami/vulndb/tree/main/data/modsecurity/BIT-modsecurity-2021-42717.json"},"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}],"schema_version":"1.7.3"}