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/ical2html-2.1/ical2html.c
Examining data/ical2html-2.1/icalfilter.c
Examining data/ical2html-2.1/icalmerge.c

FINAL RESULTS:

data/ical2html-2.1/ical2html.c:89:3:  [4] (format) vfprintf:
  If format strings can be influenced by an attacker, they can be exploited
  (CWE-134). Use a constant for the format specification.
  vfprintf(stderr, message, args);
data/ical2html-2.1/icalfilter.c:72:3:  [4] (format) vfprintf:
  If format strings can be influenced by an attacker, they can be exploited
  (CWE-134). Use a constant for the format specification.
  vfprintf(stderr, message, args);
data/ical2html-2.1/icalmerge.c:52:3:  [4] (format) vfprintf:
  If format strings can be influenced by an attacker, they can be exploited
  (CWE-134). Use a constant for the format specification.
  vfprintf(stderr, message, args);
data/ical2html-2.1/icalmerge.c:64:3:  [4] (format) vfprintf:
  If format strings can be influenced by an attacker, they can be exploited
  (CWE-134). Use a constant for the format specification.
  vfprintf(stderr, message, args);
data/ical2html-2.1/ical2html.c:486:15:  [3] (buffer) getopt_long:
  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_long(argc, argv, OPTIONS, options, NULL)) != -1) {
data/ical2html-2.1/icalfilter.c:104:15:  [3] (buffer) getopt_long:
  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_long(argc, argv, OPTIONS, options, NULL)) != -1) {
data/ical2html-2.1/icalmerge.c:265:15:  [3] (buffer) getopt_long:
  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_long(argc, argv, OPTIONS, options, NULL)) != -1) {
data/ical2html-2.1/ical2html.c:278:3:  [2] (buffer) char:
  Statically-sized arrays can be improperly restricted, leading to potential
  overflows or other issues (CWE-119!/CWE-120). Perform bounds checking, use
  functions that limit length, or ensure that the size is larger than the
  maximum possible length.
  char s[9];
data/ical2html-2.1/ical2html.c:295:7:  [2] (buffer) sprintf:
  Does not check for buffer overflows (CWE-120). Use sprintf_s, snprintf, or
  vsnprintf. Risk is low because the source has a constant maximum length.
      sprintf(s, "%04d%02d01", y, m);
data/ical2html-2.1/ical2html.c:328:2:  [2] (buffer) sprintf:
  Does not check for buffer overflows (CWE-120). Use sprintf_s, snprintf, or
  vsnprintf. Risk is low because the source has a constant maximum length.
	sprintf(s, "%04d%02d%02d", y, m, d);
data/ical2html-2.1/ical2html.c:513:37:  [2] (misc) fopen:
  Check when opening files - can an attacker redirect it (via symlinks),
  force the opening of special file type (e.g., device files), move things
  around to create a race condition, control its ancestors, or change its
  contents? (CWE-362).
  stream = optind == argc ? stdin : fopen(argv[optind], "r");
data/ical2html-2.1/icalfilter.c:115:37:  [2] (misc) fopen:
  Check when opening files - can an attacker redirect it (via symlinks),
  force the opening of special file type (e.g., device files), move things
  around to create a race condition, control its ancestors, or change its
  contents? (CWE-362).
  stream = optind == argc ? stdin : fopen(argv[optind], "r");
data/ical2html-2.1/icalmerge.c:282:14:  [2] (misc) fopen:
  Check when opening files - can an attacker redirect it (via symlinks),
  force the opening of special file type (e.g., device files), move things
  around to create a race condition, control its ancestors, or change its
  contents? (CWE-362).
    stream = fopen(argv[optind], "r");
data/ical2html-2.1/icalmerge.c:144:14:  [1] (buffer) strlen:
  Does not handle strings that are not \0-terminated; if given one it may
  perform an over-read (it could cause a crash if unprotected) (CWE-126).
  i = hval = strlen(item.key);

ANALYSIS SUMMARY:

Hits = 14
Lines analyzed = 1046 in approximately 0.08 seconds (13902 lines/second)
Physical Source Lines of Code (SLOC) = 698
Hits@level = [0]  44 [1]   1 [2]   6 [3]   3 [4]   4 [5]   0
Hits@level+ = [0+]  58 [1+]  14 [2+]  13 [3+]   7 [4+]   4 [5+]   0
Hits/KSLOC@level+ = [0+] 83.0946 [1+] 20.0573 [2+] 18.6246 [3+] 10.0287 [4+] 5.73066 [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.