Flawfinder version 2.0.10, (C) 2001-2019 David A. Wheeler.
Number of rules (primarily dangerous function names) in C/C++ ruleset: 223
Examining data/zerofree-1.1.1/zerofree.c

FINAL RESULTS:

data/zerofree-1.1.1/zerofree.c:82:4:  [4] (format) fprintf:
  If format strings can be influenced by an attacker, they can be exploited
  (CWE-134). Use a constant for the format specification.
			fprintf(stderr, USAGE, argv[0]);
data/zerofree-1.1.1/zerofree.c:88:3:  [4] (format) fprintf:
  If format strings can be influenced by an attacker, they can be exploited
  (CWE-134). Use a constant for the format specification.
		fprintf(stderr, USAGE, argv[0]);
data/zerofree-1.1.1/zerofree.c:176:3:  [4] (format) printf:
  If format strings can be influenced by an attacker, they can be exploited
  (CWE-134). Use a constant for the format specification.
		printf(FORMAT, modified, free, ext2fs_blocks_count(fs->super));
data/zerofree-1.1.1/zerofree.c:60:13:  [3] (buffer) getopt:
  Some older implementations do not protect against internal buffer overflows
  (CWE-120, CWE-20). Check implementation on installation, or limit the size
  of all string inputs.
	while ( (c=getopt(argc, argv, "nvf:")) != -1 ) {

ANALYSIS SUMMARY:

Hits = 4
Lines analyzed = 186 in approximately 0.02 seconds (9290 lines/second)
Physical Source Lines of Code (SLOC) = 141
Hits@level = [0]  12 [1]   0 [2]   0 [3]   1 [4]   3 [5]   0
Hits@level+ = [0+]  16 [1+]   4 [2+]   4 [3+]   4 [4+]   3 [5+]   0
Hits/KSLOC@level+ = [0+] 113.475 [1+] 28.3688 [2+] 28.3688 [3+] 28.3688 [4+] 21.2766 [5+]   0
Dot directories skipped = 1 (--followdotdir overrides)
Minimum risk level = 1
Not every hit is necessarily a security vulnerability.
There may be other security vulnerabilities; review your code!
See 'Secure Programming HOWTO'
(https://dwheeler.com/secure-programs) for more information.