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>

/* vi:set ts=8 sts=4 sw=4 noet:
 *
 * VIM - Vi IMproved	by Bram Moolenaar
 *
 * 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.
 */
/*
 * if_perlsfio.c: Special I/O functions for Perl interface.
 */

#define _memory_h	// avoid memset redeclaration
#define IN_PERL_FILE	// don't include if_perl.pro from prot.h

#include "vim.h"

#if defined(USE_SFIO) || defined(PROTO)

#ifndef USE_SFIO	// just generating prototypes
# define Sfio_t int
# define Sfdisc_t int
#endif

#define NIL(type)	((type)0)

    static int
sfvimwrite(
    Sfio_t	    *f,		// stream involved
    char	    *buf,	// buffer to read from
    int		    n,		// number of bytes to write
    Sfdisc_t	    *disc)	// discipline
{
    char_u *str;

    str = vim_strnsave((char_u *)buf, n);
    if (str == NULL)
	return 0;
    msg_split((char *)str);
    vim_free(str);

    return n;
}

/*
 * sfdcnewnvi --
 *  Create Vim discipline
 */
    Sfdisc_t *
sfdcnewvim(void)
{
    Sfdisc_t	*disc;

    disc = ALLOC_ONE(Sfdisc_t);
    if (disc == NULL)
	return NULL;

    disc->readf = (Sfread_f)NULL;
    disc->writef = sfvimwrite;
    disc->seekf = (Sfseek_f)NULL;
    disc->exceptf = (Sfexcept_f)NULL;

    return disc;
}

#endif // USE_SFIO