fedora 25
buffer weakness #7


Weakness Breakdown


Buffer overflows are one of the most well-known software vulnerabilities. Even though most developers know what buffer overflows are, attacks against the vulnerabilities are common in both legacy and newer applications. A classic buffer overflow exploit begins with the attacker sending data to a program, which it then stores in an undersized stack buffer. Besides stack buffer overflows, other kinds of buffer overflows include heap overflows, off-by-one errors and many others. Learn more about buffer overflows on OWASP attack index.

Warning code(s):

Does not check for buffer overflows.

File Name:



The highlighted line of code below is the trigger point of this particular Fedora 25 buffer weakness.

   xfree (username);
#if defined (HAVE_GETPWENT)
  endpwent ();
  return (dirname);

#if defined (TEST)
#undef NULL
#include <stdio.h>

main (argc, argv)
     int argc;
     char **argv;
  char *result, line[512];
  int done = 0;

  while (!done)
      printf ("~expand: ");
      fflush (stdout);

      if (!gets (line))
	strcpy (line, "done");

      if ((strcmp (line, "done") == 0) ||
	  (strcmp (line, "quit") == 0) ||
	  (strcmp (line, "exit") == 0))
	  done = 1;

      result = tilde_expand (line);
      printf ("  --> %s\n", result);
      free (result);
  exit (0);

static void memory_error_and_abort ();

static void *
xmalloc (bytes)
     size_t bytes;
  void *temp = (char *)malloc (bytes);

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