alpine 3.6
access weakness #142


Weakness Breakdown


An access weakness occurs when software does not properly implement permissions that could have unintended consequences if exploited by malicious actors. An example of this weakness is when a default username and password are set by the developer but do not get changed by the system administrator.

Warning code(s):

Ensure that umask is given most restrictive possible setting.

File Name:



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

 	dcc->file = dcc_get_download_path(dcc->arg);

	/* if some plugin wants to change the file name/path here.. */
	signal_emit("dcc get receive", 1, dcc);

	if (stat(dcc->file, &statbuf) == 0 &&
	    dcc->get_type == DCC_GET_RENAME) {
		/* file exists, rename.. */
		fname = dcc_get_rename_file(dcc->file);
		dcc->file = fname;

	if (dcc->get_type != DCC_GET_RESUME) {
		int dcc_file_create_mode = octal2dec(settings_get_int("dcc_file_create_mode"));

		/* we want to overwrite the file, remove it here.
		   if it gets created after this, we'll fail. */

		/* just to make sure we won't run into race conditions
		   if download_path is in some global temp directory */
		tempfname = g_strconcat(dcc->file, ".XXXXXX", NULL);

                old_umask = umask(0077);
		temphandle = mkstemp(tempfname);

		if (temphandle == -1)
			ret = -1;
			ret = fchmod(temphandle, dcc_file_create_mode);


		if (ret != -1) {
			ret = link(tempfname, dcc->file);

			if (ret == -1 &&
			    /* Linux */
			    (errno == EPERM ||
			     /* FUSE */
			     errno == ENOSYS ||
			     /* BSD */
			     errno == EOPNOTSUPP)) {
				/* hard links aren't supported - some people
				   want to download stuff to FAT/NTFS/etc
				   partitions, so fallback to rename() */
				ret = rename(tempfname, dcc->file);

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