cJSON through 1.7.19 is vulnerable to uncontrolled recursion leading to stack exhaustion when an untrusted RFC 6902 JSON Patch is applied via cJSONUtils_ApplyPatches() or cJSONUtils_ApplyPatchesCaseSensitive(). A patch containing add and copy operations grafts duplicated subtrees to amplify document depth beyond the parsers nesting limit: cJSON_Delete() recurses with no depth bound, and the cJSON_Duplicate() guard CJSON_CIRCULAR_LIMIT is set to 10000, ten times the parsers 1000-level nesting limit and high enough to overflow a default thread stack. An attacker who can supply the patch document can crash the process, resulting in denial of service.
Weakness
The product does not properly control the amount of recursion that takes place, consuming excessive resources, such as allocated memory or the program stack.
Potential Mitigations
Related Attack Patterns
References
- https://github.com/DaveGamble/cJSON/blob/v1.7.19/cJSON.c#L253-L261
- https://github.com/DaveGamble/cJSON/blob/v1.7.19/cJSON_Utils.c#L906-L940
- https://joshua.hu/cjson-json-parser-cve-vulnerabilities
- https://www.vulncheck.com/advisories/cjson-json-patch-copy-add-uncontrolled-recursion-stack-exhaustion
- https://joshua.hu/cjson-json-parser-cve-vulnerabilities