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.
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describes (1)
Related CVEs.
| ID | severity | exploitable | ||
|---|---|---|---|---|
| CVE-2021-42717US | high7.5 | Exploit | ||
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 se… | ||||
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references
External citations — patches, advisories, analysis.
- https://lists.debian.org/debian-lts-announce/2022/05/msg00042.htmlADVISORY
- https://nvd.nist.gov/vuln/detail/CVE-2021-42717WEB
- https://www.debian.org/security/2021/dsa-5023ADVISORY
- https://www.oracle.com/security-alerts/cpuapr2022.htmlADVISORY
- https://www.trustwave.com/en-us/resources/blogs/spiderlabs-blog/modsecurity-dos-vulnerability-in-json-parsing-cve-2021-42717/ADVISORY
scry
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