cJSON through 1.7.19 applies RFC 6902 JSON Patch operations non-atomically in apply_patch() in cJSON_Utils.c. For a replace operation that is missing its value member, or a move operation whose destination path cannot be resolved, the existing target member is detached and deleted before the operation is fully validated, so the target document is mutated while cJSONUtils_ApplyPatches() or cJSONUtils_ApplyPatchesCaseSensitive() returns a failure status. An attacker who can supply the patch document can destroy addressable members of the target document even though the API reports that the patch failed, defeating the all-or-nothing behavior callers rely on to reject bad patches.

cJSON through 1.7.19 contains an inefficient algorithmic complexity flaw in cJSON_Compare(). When comparing objects, the function recurses into each shared subtree twice, once in each direction, with no depth guard, making the running time exponential in nesting depth. A small, deeply nested document of a few hundred bytes (depth around 40) compared for equality consumes hours of CPU, and the cost roughly doubles with each additional level of nesting. An application that calls cJSON_Compare() on attacker-influenced JSON that is structurally equal to a reference document is exposed to a denial-of-service condition.

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 parser's nesting limit: cJSON_Delete() recurses with no depth bound, and the cJSON_Duplicate() guard CJSON_CIRCULAR_LIMIT is set to 10000, ten times the parser's 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.

cJSON 1.5.0 through 1.7.18 allows out-of-bounds access via the decode_array_index_from_pointer function in cJSON_Utils.c, allowing remote attackers to bypass array bounds checking and access restricted data via malformed JSON pointer strings containing alphanumeric characters.

cJSON v1.7.16 was discovered to contain a segmentation violation via the function cJSON_SetValuestring at cJSON.c.

cJSON v1.7.16 was discovered to contain a segmentation violation via the function cJSON_InsertItemInArray at cJSON.c.

DaveGamble/cJSON cJSON 1.7.8 is affected by: Improper Check for Unusual or Exceptional Conditions. The impact is: Null dereference, so attack can cause denial of service. The component is: cJSON_GetObjectItemCaseSensitive() function. The attack vector is: crafted json file. The fixed version is: 1.7.9 and later.

cJSON before 1.7.11 allows out-of-bounds access, related to multiline comments.

cJSON before 1.7.11 allows out-of-bounds access, related to \x00 in a string literal.

parse_string in cJSON.c in cJSON before 2016-10-02 has a buffer over-read, as demonstrated by a string that begins with a " character and ends with a \ character.

Dave Gamble cJSON version 1.7.3 and earlier contains a CWE-416: Use After Free vulnerability in cJSON library that can result in Possible crash, corruption of data or even RCE. This attack appear to be exploitable via Depends on how application uses cJSON library. If application provides network interface then can be exploited over a network, otherwise just local.. This vulnerability appears to have been fixed in 1.7.4.

Dave Gamble cJSON version 1.7.2 and earlier contains a CWE-415: Double Free vulnerability in cJSON library that can result in Possible crash or RCE. This attack appear to be exploitable via Attacker must be able to force victim to print JSON data, depending on how cJSON library is used this could be either local or over a network. This vulnerability appears to have been fixed in 1.7.3.

Dave Gamble cJSON version 1.7.6 and earlier contains a CWE-772 vulnerability in cJSON library that can result in Denial of Service (DoS). This attack appear to be exploitable via If the attacker can force the data to be printed and the system is in low memory it can force a leak of memory. This vulnerability appears to have been fixed in 1.7.7.