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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-7.1.1.orig/ext/standard/exec.c php-7.1.1/ext/standard/exec.c
--- php-7.1.1.orig/ext/standard/exec.c 2017-01-17 21:44:37.000000000 +0100
+++ php-7.1.1/ext/standard/exec.c 2017-02-16 18:02:43.379106453 +0100
@@ -96,21 +96,30 @@
char *buf;
size_t l = 0;
int 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))) {
+ zend_string *cmd_esc = php_escape_shell_arg(cmd);
+ spprintf(&d, 0, "PATH=%s /bin/bash --php -rc %s", PG(exec_dir), ZSTR_VAL(cmd_esc));
+ zend_string_release(cmd_esc);
+ 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, E_WARNING, "Unable to fork [%s]", cmd);
@@ -515,7 +524,7 @@
PHP_FUNCTION(shell_exec)
{
FILE *in;
- char *command;
+ char *command, *command_p;
size_t command_len;
zend_string *ret;
php_stream *stream;
@@ -524,14 +533,24 @@
return;
}
+ if (PG(exec_dir) && strlen(PG(exec_dir))) {
+ zend_string *cmd_esc = php_escape_shell_arg(command);
+ spprintf(&command_p, 0, "PATH=%s /bin/bash --php -rc %s", PG(exec_dir), ZSTR_VAL(cmd_esc));
+ zend_string_release(cmd_esc);
+ } 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, E_WARNING, "Unable to execute '%s'", command);
+ efree(command_p);
RETURN_FALSE;
}
+ efree(command_p);
stream = php_stream_fopen_from_pipe(in, "rb");
ret = php_stream_copy_to_mem(stream, PHP_STREAM_COPY_ALL, 0);
diff -Naur php-7.1.1.orig/ext/standard/file.c php-7.1.1/ext/standard/file.c
--- php-7.1.1.orig/ext/standard/file.c 2017-01-17 21:44:37.000000000 +0100
+++ php-7.1.1/ext/standard/file.c 2017-02-16 18:02:43.380106442 +0100
@@ -927,7 +927,16 @@
}
#endif
- fp = VCWD_POPEN(command, posix_mode);
+ if (PG(exec_dir) && strlen(PG(exec_dir))) {
+ zend_string *cmd_esc = php_escape_shell_arg(command);
+ char *tmp;
+ spprintf(&tmp, 0, "PATH=%s /bin/bash --php -rc %s", PG(exec_dir), ZSTR_VAL(cmd_esc));
+ fp = VCWD_POPEN(tmp, posix_mode);
+ efree(tmp);
+ zend_string_release(cmd_esc);
+ } else {
+ fp = VCWD_POPEN(command, posix_mode);
+ }
if (!fp) {
php_error_docref2(NULL, command, posix_mode, E_WARNING, "%s", strerror(errno));
efree(posix_mode);
diff -Naur php-7.1.1.orig/ext/standard/filestat.c php-7.1.1/ext/standard/filestat.c
--- php-7.1.1.orig/ext/standard/filestat.c 2017-01-17 21:44:37.000000000 +0100
+++ php-7.1.1/ext/standard/filestat.c 2017-02-16 18:03:10.015802863 +0100
@@ -771,13 +771,14 @@
"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)) == &php_plain_files_wrapper && php_check_open_basedir(local)) {
+ if ((wrapper = php_stream_locate_url_wrapper(filename, &local, 0)) == &php_plain_files_wrapper && type != FS_IS_X && php_check_open_basedir(local)) {
RETURN_FALSE;
}
@@ -802,6 +803,19 @@
#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-7.1.1.orig/ext/standard/proc_open.c php-7.1.1/ext/standard/proc_open.c
--- php-7.1.1.orig/ext/standard/proc_open.c 2017-01-17 21:44:35.000000000 +0100
+++ php-7.1.1/ext/standard/proc_open.c 2017-02-16 18:02:43.381106430 +0100
@@ -493,6 +493,15 @@
command_len = strlen(command);
+ zval envpath;
+ if (PG(exec_dir) && strlen(PG(exec_dir))) {
+ if (!environment) {
+ array_init_size(&envpath, 1);
+ environment = &envpath;
+ }
+ add_assoc_string(environment, "PATH", PG(exec_dir));
+ }
+
if (environment) {
env = _php_array_to_envp(environment, is_persistent);
} else {
@@ -891,10 +900,14 @@
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-7.1.1.orig/main/main.c php-7.1.1/main/main.c
--- php-7.1.1.orig/main/main.c 2017-01-17 21:44:42.000000000 +0100
+++ php-7.1.1/main/main.c 2017-02-16 18:02:43.382106419 +0100
@@ -616,6 +616,7 @@
#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-7.1.1.orig/main/php_globals.h php-7.1.1/main/php_globals.h
--- php-7.1.1.orig/main/php_globals.h 2017-01-17 21:44:42.000000000 +0100
+++ php-7.1.1/main/php_globals.h 2017-02-16 18:02:43.382106419 +0100
@@ -167,6 +167,7 @@
#ifdef PHP_WIN32
zend_bool windows_show_crt_warning;
#endif
+ char *exec_dir;
};
diff -Naur php-7.1.1.orig/php.ini-development php-7.1.1/php.ini-development
--- php-7.1.1.orig/php.ini-development 2017-01-17 21:44:41.000000000 +0100
+++ php-7.1.1/php.ini-development 2017-02-16 18:02:43.383106408 +0100
@@ -308,6 +308,10 @@
; 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-7.1.1.orig/php.ini-production php-7.1.1/php.ini-production
--- php-7.1.1.orig/php.ini-production 2017-01-17 21:44:41.000000000 +0100
+++ php-7.1.1/php.ini-production 2017-02-16 18:02:43.384106396 +0100
@@ -308,6 +308,10 @@
; 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