fix the incorrect check in decode_array_index_from_pointer (#957)

PeterAlfredLee · web-flow · commit 74e1ff4994aa · 2025-09-05T14:53:20.000+08:00
this fixes CVE-2025-57052
diff --git a/cJSON_Utils.c b/cJSON_Utils.c
@@ -282,7 +282,7 @@ static cJSON_bool decode_array_index_from_pointer(const unsigned char * const po
         return 0;
     }
 
-    for (position = 0; (pointer[position] >= '0') && (pointer[0] <= '9'); position++)
+    for (position = 0; (pointer[position] >= '0') && (pointer[position] <= '9'); position++)
     {
         parsed_index = (10 * parsed_index) + (size_t)(pointer[position] - '0');
 

Original file line number	Diff line number	Diff line change
`@@ -282,7 +282,7 @@ static cJSON_bool decode_array_index_from_pointer(const unsigned char * const po`
`282`	`282`	`return 0;`
`283`	`283`	`}`
`284`	`284`
`285`		`- for (position = 0; (pointer[position] >= '0') && (pointer[0] <= '9'); position++)`
	`285`	`+ for (position = 0; (pointer[position] >= '0') && (pointer[position] <= '9'); position++)`
`286`	`286`	`{`
`287`	`287`	`parsed_index = (10 * parsed_index) + (size_t)(pointer[position] - '0');`
`288`	`288`