centos 7
tmpfile weakness #22

4

Weakness Breakdown


Definition:

A temporary file weakness occurs when a temporary file that is created and used by a high-privilege process is accidentally shared with a low-privilege process, on account of it being temporary and generated after all security controls have been applied. This allows the low-privilege process to read data from the high-privilege process (information leakage), or worse, influence the high-privilege process by modifying the shared temporary file.

Warning code(s):

Temporary file race condition.

File Name:

make-3.82/main.c

Context:

The highlighted line of code below is the trigger point of this particular Centos 7 tmpfile weakness.

 
FILE *
open_tmpfile(char **name, const char *template)
{
#ifdef HAVE_FDOPEN
  int fd;
#endif

#if defined HAVE_MKSTEMP || defined HAVE_MKTEMP
# define TEMPLATE_LEN   strlen (template)
#else
# define TEMPLATE_LEN   L_tmpnam
#endif
  *name = xmalloc (TEMPLATE_LEN + 1);
  strcpy (*name, template);

#if defined HAVE_MKSTEMP && defined HAVE_FDOPEN
  /* It's safest to use mkstemp(), if we can.  */
  fd = mkstemp (*name);
  if (fd == -1)
    return 0;
  return fdopen (fd, "w");
#else
# ifdef HAVE_MKTEMP
  (void) mktemp (*name);
# else
  (void) tmpnam (*name);
# endif

# ifdef HAVE_FDOPEN
  /* Can't use mkstemp(), but guard against a race condition.  */
  fd = open (*name, O_CREAT|O_EXCL|O_WRONLY, 0600);
  if (fd == -1)
    return 0;
  return fdopen (fd, "w");
# else
  /* Not secure, but what can we do?  */
  return fopen (*name, "w");
# endif
#endif
}


#ifdef _AMIGA
int
main (int argc, char **argv)
#else
int
main (int argc, char **argv, char **envp)
#endif 

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