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/flannel-0.9.1~ds1/backend/udp/proxy.c
Examining data/flannel-0.9.1~ds1/backend/udp/proxy.h

FINAL RESULTS:

data/flannel-0.9.1~ds1/backend/udp/proxy.c:77:3:  [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, fmt, ap);
data/flannel-0.9.1~ds1/backend/udp/proxy.c:49:2:  [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    data[sizeof(struct iphdr) + MAX_IPOPTLEN + 8];
data/flannel-0.9.1~ds1/backend/udp/proxy.c:147:2:  [2] (buffer) memcpy:
  Does not check for buffer overflows when copying to destination (CWE-120).
  Make sure destination can always hold the source data.
	memcpy(pkt.data, offender, off_iph_len + 8);
data/flannel-0.9.1~ds1/backend/udp/proxy.c:298:3:  [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 saddr[32], daddr[32];
data/flannel-0.9.1~ds1/backend/udp/proxy.c:227:2:  [1] (buffer) strncpy:
  Easily used incorrectly; doesn't always \0-terminate or check for invalid
  pointers [MS-banned] (CWE-120).
	strncpy(buf, inet_ntoa(addr), len);
data/flannel-0.9.1~ds1/backend/udp/proxy.c:234:18:  [1] (buffer) read:
  Check buffer boundaries if used in a loop including recursive loops
  (CWE-120, CWE-20).
	ssize_t nread = read(tun, buf, buflen);

ANALYSIS SUMMARY:

Hits = 6
Lines analyzed = 505 in approximately 0.22 seconds (2342 lines/second)
Physical Source Lines of Code (SLOC) = 351
Hits@level = [0]   2 [1]   2 [2]   3 [3]   0 [4]   1 [5]   0
Hits@level+ = [0+]   8 [1+]   6 [2+]   4 [3+]   1 [4+]   1 [5+]   0
Hits/KSLOC@level+ = [0+] 22.792 [1+] 17.094 [2+] 11.396 [3+] 2.849 [4+] 2.849 [5+]   0
Dot directories skipped = 2 (--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.