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This patch is based on http://kyberdigi.cz/projects/execdir/ but instead trying
to sanitize the exec command string inside PHP this job is handled by bash and
a special restricted PHP-mode which strips off all path informations.
This patch depends on:
- bash restricted php mode patch
https://manuel.mausz.at/coding/patches/php/bash-4.2-restricted-php.patch
No warranty!
diff -Naur php-5.6.30.orig/ext/standard/exec.c php-5.6.30/ext/standard/exec.c
--- php-5.6.30.orig/ext/standard/exec.c 2017-01-19 01:17:47.000000000 +0100
+++ php-5.6.30/ext/standard/exec.c 2017-02-16 18:05:58.948877544 +0100
@@ -105,21 +105,30 @@
FILE *fp;
char *buf;
int l = 0, pclose_return;
- char *b, *d=NULL;
+ char *cmd_p, *b, *d=NULL;
php_stream *stream;
size_t buflen, bufl = 0;
#if PHP_SIGCHILD
void (*sig_handler)() = NULL;
#endif
+ if (PG(exec_dir) && strlen(PG(exec_dir))) {
+ cmd_p = php_escape_shell_arg(cmd);
+ spprintf(&d, 0, "PATH=%s /bin/bash --php -rc %s", PG(exec_dir), cmd_p);
+ efree(cmd_p);
+ cmd_p = d;
+ } else {
+ cmd_p = cmd;
+ }
+
#if PHP_SIGCHILD
sig_handler = signal (SIGCHLD, SIG_DFL);
#endif
#ifdef PHP_WIN32
- fp = VCWD_POPEN(cmd, "rb");
+ fp = VCWD_POPEN(cmd_p, "rb");
#else
- fp = VCWD_POPEN(cmd, "r");
+ fp = VCWD_POPEN(cmd_p, "r");
#endif
if (!fp) {
php_error_docref(NULL TSRMLS_CC, E_WARNING, "Unable to fork [%s]", cmd);
@@ -528,7 +537,7 @@
{
FILE *in;
size_t total_readbytes;
- char *command;
+ char *command, *command_p;
int command_len;
char *ret;
php_stream *stream;
@@ -537,14 +546,24 @@
return;
}
+ if (PG(exec_dir) && strlen(PG(exec_dir))) {
+ char *d = php_escape_shell_arg(command);
+ spprintf(&command_p, 0, "PATH=%s /bin/bash --php -rc %s", PG(exec_dir), d);
+ efree(d);
+ } else {
+ command_p = estrdup(command);
+ }
+
#ifdef PHP_WIN32
- if ((in=VCWD_POPEN(command, "rt"))==NULL) {
+ if ((in=VCWD_POPEN(command_p, "rt"))==NULL) {
#else
- if ((in=VCWD_POPEN(command, "r"))==NULL) {
+ if ((in=VCWD_POPEN(command_p, "r"))==NULL) {
#endif
php_error_docref(NULL TSRMLS_CC, E_WARNING, "Unable to execute '%s'", command);
+ efree(command_p);
RETURN_FALSE;
}
+ efree(command_p);
stream = php_stream_fopen_from_pipe(in, "rb");
total_readbytes = php_stream_copy_to_mem(stream, &ret, PHP_STREAM_COPY_ALL, 0);
diff -Naur php-5.6.30.orig/ext/standard/file.c php-5.6.30/ext/standard/file.c
--- php-5.6.30.orig/ext/standard/file.c 2017-01-19 01:17:47.000000000 +0100
+++ php-5.6.30/ext/standard/file.c 2017-02-16 18:05:58.949877533 +0100
@@ -944,7 +944,16 @@
}
#endif
- fp = VCWD_POPEN(command, posix_mode);
+ if (PG(exec_dir) && strlen(PG(exec_dir))) {
+ char *command_p, *tmp;
+ command_p = php_escape_shell_arg(command);
+ spprintf(&tmp, 0, "PATH=%s /bin/bash --php -rc %s", PG(exec_dir), command_p);
+ fp = VCWD_POPEN(tmp, posix_mode);
+ efree(tmp);
+ efree(command_p);
+ } else {
+ fp = VCWD_POPEN(command, posix_mode);
+ }
if (!fp) {
php_error_docref2(NULL TSRMLS_CC, command, posix_mode, E_WARNING, "%s", strerror(errno));
efree(posix_mode);
diff -Naur php-5.6.30.orig/ext/standard/filestat.c php-5.6.30/ext/standard/filestat.c
--- php-5.6.30.orig/ext/standard/filestat.c 2017-01-19 01:17:47.000000000 +0100
+++ php-5.6.30/ext/standard/filestat.c 2017-02-16 18:06:23.005603384 +0100
@@ -858,13 +858,14 @@
"size", "atime", "mtime", "ctime", "blksize", "blocks"
};
const char *local;
+ char local_safe[MAXPATHLEN];
php_stream_wrapper *wrapper;
if (!filename_length) {
RETURN_FALSE;
}
- if ((wrapper = php_stream_locate_url_wrapper(filename, &local, 0 TSRMLS_CC)) == &php_plain_files_wrapper && php_check_open_basedir(local TSRMLS_CC)) {
+ if ((wrapper = php_stream_locate_url_wrapper(filename, &local, 0 TSRMLS_CC)) == &php_plain_files_wrapper && type != FS_IS_X && php_check_open_basedir(local TSRMLS_CC)) {
RETURN_FALSE;
}
@@ -889,6 +890,19 @@
#endif
#ifdef X_OK
case FS_IS_X:
+ if (PG(exec_dir) && strlen(PG(exec_dir))) {
+ if (strstr(local, "..")) {
+ RETURN_FALSE;
+ } else {
+ char *b = strrchr(local, PHP_DIR_SEPARATOR);
+ if (b) {
+ snprintf(local_safe, MAXPATHLEN, "%s%s", PG(exec_dir), b);
+ } else {
+ snprintf(local_safe, MAXPATHLEN, "%s%c%s", PG(exec_dir), PHP_DIR_SEPARATOR, local);
+ }
+ local = (char *)&local_safe;
+ }
+ }
RETURN_BOOL(VCWD_ACCESS(local, X_OK) == 0);
break;
#endif
diff -Naur php-5.6.30.orig/ext/standard/proc_open.c php-5.6.30/ext/standard/proc_open.c
--- php-5.6.30.orig/ext/standard/proc_open.c 2017-01-19 01:17:47.000000000 +0100
+++ php-5.6.30/ext/standard/proc_open.c 2017-02-16 18:05:58.950877521 +0100
@@ -521,6 +521,14 @@
command_len = strlen(command);
+ if (PG(exec_dir) && strlen(PG(exec_dir))) {
+ if (!environment) {
+ MAKE_STD_ZVAL(environment);
+ array_init_size(environment, 1);
+ }
+ add_assoc_string(environment, "PATH", PG(exec_dir), 1);
+ }
+
if (environment) {
env = _php_array_to_envp(environment, is_persistent TSRMLS_CC);
} else {
@@ -880,10 +888,14 @@
php_ignore_value(chdir(cwd));
}
- if (env.envarray) {
- execle("/bin/sh", "sh", "-c", command, NULL, env.envarray);
+ if (PG(exec_dir) && strlen(PG(exec_dir))) {
+ execle("/bin/bash", "bash", "--php", "-rc", command, NULL, env.envarray);
} else {
- execl("/bin/sh", "sh", "-c", command, NULL);
+ if (env.envarray) {
+ execle("/bin/sh", "sh", "-c", command, NULL, env.envarray);
+ } else {
+ execl("/bin/sh", "sh", "-c", command, NULL);
+ }
}
_exit(127);
diff -Naur php-5.6.30.orig/main/main.c php-5.6.30/main/main.c
--- php-5.6.30.orig/main/main.c 2017-01-19 01:17:47.000000000 +0100
+++ php-5.6.30/main/main.c 2017-02-16 18:05:58.951877510 +0100
@@ -643,6 +643,7 @@
#ifdef PHP_WIN32
STD_PHP_INI_BOOLEAN("windows.show_crt_warning", "0", PHP_INI_ALL, OnUpdateBool, windows_show_crt_warning, php_core_globals, core_globals)
#endif
+ STD_PHP_INI_ENTRY("exec_dir", NULL, PHP_INI_SYSTEM, OnUpdateString, exec_dir, php_core_globals, core_globals)
PHP_INI_END()
/* }}} */
diff -Naur php-5.6.30.orig/main/php_globals.h php-5.6.30/main/php_globals.h
--- php-5.6.30.orig/main/php_globals.h 2017-01-19 01:17:47.000000000 +0100
+++ php-5.6.30/main/php_globals.h 2017-02-16 18:05:58.951877510 +0100
@@ -167,6 +167,7 @@
#ifdef PHP_WIN32
zend_bool windows_show_crt_warning;
#endif
+ char *exec_dir;
};
diff -Naur php-5.6.30.orig/php.ini-development php-5.6.30/php.ini-development
--- php-5.6.30.orig/php.ini-development 2017-01-19 01:17:47.000000000 +0100
+++ php-5.6.30/php.ini-development 2017-02-16 18:05:58.952877499 +0100
@@ -297,6 +297,10 @@
; http://php.net/open-basedir
;open_basedir =
+; Only executables located in the exec_dir will be allowed to be executed
+; via the exec family of functions.
+exec_dir =
+
; This directive allows you to disable certain functions for security reasons.
; It receives a comma-delimited list of function names.
; http://php.net/disable-functions
diff -Naur php-5.6.30.orig/php.ini-production php-5.6.30/php.ini-production
--- php-5.6.30.orig/php.ini-production 2017-01-19 01:17:47.000000000 +0100
+++ php-5.6.30/php.ini-production 2017-02-16 18:05:58.953877487 +0100
@@ -297,6 +297,10 @@
; http://php.net/open-basedir
;open_basedir =
+; Only executables located in the exec_dir will be allowed to be executed
+; via the exec family of functions.
+exec_dir =
+
; This directive allows you to disable certain functions for security reasons.
; It receives a comma-delimited list of function names.
; http://php.net/disable-functions