alpine 3.6
tmpfile weakness #25

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:

ruby/src/ruby-2.4.6/ext/nkf/nkf-utf8/nkf.h

Context:

The highlighted line of code below is the trigger point of this particular Alpine 3.6 tmpfile weakness.

 #endif

#if (defined(__TURBOC__) || defined(_MSC_VER) || defined(LSI_C) || (defined(__WATCOMC__) && defined(__386__) && !defined(__LINUX__)) || defined(__MINGW32__) || defined(__EMX__) || defined(__MSDOS__) || defined(__WINDOWS__) || defined(__DOS__) || defined(__OS2__)) && !defined(MSDOS)
#define MSDOS
#if (defined(__Win32__) || defined(_WIN32)) && !defined(__WIN32__)
#define __WIN32__
#endif
#endif

#ifdef PERL_XS
#undef OVERWRITE
#endif

#ifndef PERL_XS
#include <stdio.h>
#endif

#include <stdlib.h>
#include <string.h>

#if defined(MSDOS) || defined(__OS2__)
#include <fcntl.h>
#include <io.h>
#if defined(_MSC_VER) || defined(__WATCOMC__)
#define mktemp _mktemp
#endif
#endif

#ifdef MSDOS
#ifdef LSI_C
#define setbinmode(fp) fsetbin(fp)
#elif defined(__DJGPP__)
#include <libc/dosio.h>
void  setbinmode(FILE *fp)
{
    /* we do not use libc's setmode(), which changes COOKED/RAW mode in device. */
    int fd, m;
    fd = fileno(fp);
    m = (__file_handle_modes[fd] & (~O_TEXT)) | O_BINARY;
    __file_handle_set(fd, m);
}
#else /* Microsoft C, Turbo C */
#define setbinmode(fp) setmode(fileno(fp), O_BINARY)
#endif
#else /* UNIX */
#define setbinmode(fp) (void)(fp)
#endif

#ifdef _IOFBF /* SysV and MSDOS, Windows */
#define       setvbuffer(fp, buf, size)       setvbuf(fp, buf, _IOFBF, size) 

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