Code: static double ipow( double n, int exp )
 {
	double r;
 
	if ( exp < 0 )
		return 1.0 / ipow( n, -exp );
	r = 1;
	while ( exp > 0 ) {
		if ( exp & 1 )
			r *= n;
		exp >>= 1;
		n *= n;
 	}
	return r;
}

Vulnerability Type: DoS Exec Code Overflow 
CWE ID: CWE-119
Summary: The parse_string function in cjson.c in the cJSON library mishandles UTF8/16 strings, which allows remote attackers to cause a denial of service (crash) or execute arbitrary code via a non-hex character in a JSON string, which triggers a heap-based buffer overflow.
Commit Message: Fix a buffer overflow / heap corruption issue that could occur if a
malformed JSON string was passed on the control channel.  This issue,
present in the cJSON library, was already fixed upstream, so was
addressed here in iperf3 by importing a newer version of cJSON (plus
local ESnet modifications).

Discovered and reported by Dave McDaniel, Cisco Talos.

Based on a patch by @dopheide-esnet, with input from @DaveGamble.

Cross-references:  TALOS-CAN-0164, ESNET-SECADV-2016-0001,
CVE-2016-4303

(cherry picked from commit ed94082be27d971a5e1b08b666e2c217cf470a40)
Signed-off-by: Bruce A. Mah <bmah@es.net>