view src/vimrun.c @ 33664:06b59278bfcf v9.0.2070

patch 9.0.2070: [security] disallow setting env in restricted mode Commit: https://github.com/vim/vim/commit/6b89dd6a7257a1e2e9c7ea070b407bc4674a5118 Author: Christian Brabandt <cb@256bit.org> Date: Thu Oct 26 22:14:17 2023 +0200 patch 9.0.2070: [security] disallow setting env in restricted mode Problem: [security] disallow setting env in restricted mode Solution: Setting environment variables in restricted mode could potentially be used to execute shell commands. Disallow this. restricted mode: disable allow setting of environment variables Setting environment variables in restricted mode, may have some unwanted consequences. So, for example by setting $GCONV_PATH in restricted mode and then calling the iconv() function, one may be able to execute some unwanted payload, because the `iconv_open()` function internally uses the `$GCONV_PATH` variable to find its conversion data. So let's disable setting environment variables, even so this is no complete protection, since we are not clearing the existing environment. I tried a few ways but wasn't successful :( One could also argue to disable the iconv() function completely in restricted mode, but who knows what other API functions can be influenced by setting some other unrelated environment variables. So let's leave it as it is currently. closes: #13394 See: https://huntr.com/bounties/b0a2eda1-459c-4e36-98e6-0cc7d7faccfe/ Signed-off-by: Christian Brabandt <cb@256bit.org>
author Christian Brabandt <cb@256bit.org>
date Thu, 26 Oct 2023 22:30:03 +0200
parents 2559dc02bd64
children
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/* vi:set ts=8 sts=4 sw=4 noet:
 *
 * VIM - Vi IMproved	by Bram Moolenaar
 *			this file by Vince Negri
 *
 * Do ":help uganda"  in Vim to read copying and usage conditions.
 * Do ":help credits" in Vim to see a list of people who contributed.
 * See README.txt for an overview of the Vim source code.
 */

/*
 * vimrun.c - Tiny Win32 program to safely run an external command in a
 *	      DOS console.
 *	      This program is required to avoid that typing CTRL-C in the DOS
 *	      console kills Vim.  Now it only kills vimrun.
 */

#include <stdio.h>
#include <stdlib.h>
#include <conio.h>
#ifndef WIN32_LEAN_AND_MEAN
# define WIN32_LEAN_AND_MEAN
#endif
#include <windows.h>

    int
main(void)
{
    const wchar_t   *p;
    wchar_t	    *cmd;
    size_t	    cmdlen;
    int		    retval;
    int		    inquote = 0;
    int		    silent = 0;
    HANDLE	    hstdout;
    DWORD	    written;

    p = (const wchar_t *)GetCommandLineW();

    /*
     * Skip the executable name, which might be in "".
     */
    while (*p)
    {
	if (*p == L'"')
	    inquote = !inquote;
	else if (!inquote && *p == L' ')
	{
	    ++p;
	    break;
	}
	++p;
    }
    while (*p == L' ')
	++p;

    /*
     * "-s" argument: don't wait for a key hit.
     */
    if (p[0] == L'-' && p[1] == L's' && p[2] == L' ')
    {
	silent = 1;
	p += 3;
	while (*p == L' ')
	    ++p;
    }

    // Print the command, including quotes and redirection.
    hstdout = GetStdHandle(STD_OUTPUT_HANDLE);
    WriteConsoleW(hstdout, p, wcslen(p), &written, NULL);
    WriteConsoleW(hstdout, L"\r\n", 2, &written, NULL);

    // If the command starts and ends with double quotes,
    // Enclose the command in parentheses.
    cmd = NULL;
    cmdlen = wcslen(p);
    if (cmdlen >= 2 && p[0] == L'"' && p[cmdlen - 1] == L'"')
    {
	cmdlen += 3;
	cmd = malloc(cmdlen * sizeof(wchar_t));
	if (cmd == NULL)
	{
	    perror("vimrun malloc(): ");
	    return -1;
	}
	_snwprintf(cmd, cmdlen, L"(%s)", p);
	p = cmd;
    }

    /*
     * Do it!
     */
    retval = _wsystem(p);

    if (cmd)
	free(cmd);

    if (retval == -1)
	perror("vimrun system(): ");
    else if (retval != 0)
	printf("shell returned %d\n", retval);

    if (!silent)
    {
	puts("Hit any key to close this window...");

	while (_kbhit())
	    (void)_getch();
	(void)_getch();
    }

    return retval;
}