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Add XSS attack protect in magic variables $_GET and $_POST #19047

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Add XSS attack protect in magic variables $_GET and $_POST #19047

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15ddc5b
Add XSS attack protect in magic variables $_GET and $_POST
Ange1PLSGreet Jul 6, 2025
5e5ec45
Modify the implicit declaration of the function
Ange1PLSGreet Jul 6, 2025
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210 changes: 114 additions & 96 deletions main/php_variables.c
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Original file line number Diff line number Diff line change
Expand Up @@ -33,6 +33,18 @@ static void _php_load_environment_variables(zval *array_ptr);
PHPAPI void (*php_import_environment_variables)(zval *array_ptr) = _php_import_environment_variables;
PHPAPI void (*php_load_environment_variables)(zval *array_ptr) = _php_load_environment_variables;


void php_sanitize_value(char *value, size_t len) {
size_t write_index = 0;
for (size_t read_index = 0; read_index < len; read_index++) {
if (value[read_index] != '<' && value[read_index] != '>' && value[read_index] != '/') {
value[write_index] = value[read_index];
write_index++;
}
}
value[write_index] = '\0';
}

PHPAPI void php_register_variable(const char *var, const char *strval, zval *track_vars_array)
{
php_register_variable_safe(var, strval, strlen(strval), track_vars_array);
Expand Down Expand Up @@ -105,6 +117,7 @@ static bool php_is_forbidden_variable_name(const char *mangled_name, size_t mang
return false;
}


PHPAPI void php_register_variable_ex(const char *var_name, zval *val, zval *track_vars_array)
{
char *p = NULL;
Expand Down Expand Up @@ -341,55 +354,59 @@ typedef struct post_var_data {

static bool add_post_var(zval *arr, post_var_data_t *var, bool eof)
{
char *start, *ksep, *vsep, *val;
size_t klen, vlen;
size_t new_vlen;

if (var->ptr >= var->end) {
return 0;
}

start = var->ptr + var->already_scanned;
vsep = memchr(start, '&', var->end - start);
if (!vsep) {
if (!eof) {
var->already_scanned = var->end - var->ptr;
return 0;
} else {
vsep = var->end;
}
}

ksep = memchr(var->ptr, '=', vsep - var->ptr);
if (ksep) {
*ksep = '\0';
/* "foo=bar&" or "foo=&" */
klen = ksep - var->ptr;
vlen = vsep - ++ksep;
} else {
ksep = "";
/* "foo&" */
klen = vsep - var->ptr;
vlen = 0;
}

php_url_decode(var->ptr, klen);

val = estrndup(ksep, vlen);
if (vlen) {
vlen = php_url_decode(val, vlen);
}

if (sapi_module.input_filter(PARSE_POST, var->ptr, &val, vlen, &new_vlen)) {
php_register_variable_safe(var->ptr, val, new_vlen, arr);
}
efree(val);

var->ptr = vsep + (vsep != var->end);
var->already_scanned = 0;
return 1;
char *start, *ksep, *vsep, *val;
size_t klen, vlen;
size_t new_vlen;

if (var->ptr >= var->end) {
return 0;
}

start = var->ptr + var->already_scanned;
vsep = memchr(start, '&', var->end - start);
if (!vsep) {
if (!eof) {
var->already_scanned = var->end - var->ptr;
return 0;
} else {
vsep = var->end;
}
}

ksep = memchr(var->ptr, '=', vsep - var->ptr);
if (ksep) {
*ksep = '\0';
/* "foo=bar&" or "foo=&" */
klen = ksep - var->ptr;
vlen = vsep - ++ksep;
} else {
ksep = "";
/* "foo&" */
klen = vsep - var->ptr;
vlen = 0;
}

php_url_decode(var->ptr, klen);

val = estrndup(ksep, vlen);
if (vlen) {
vlen = php_url_decode(val, vlen);
}

php_sanitize_value(val, vlen);
vlen = strlen(val);

if (sapi_module.input_filter(PARSE_POST, var->ptr, &val, vlen, &new_vlen)) {
php_register_variable_safe(var->ptr, val, new_vlen, arr);
}
efree(val);

var->ptr = vsep + (vsep != var->end);
var->already_scanned = 0;
return 1;
}


static inline int add_post_vars(zval *arr, post_var_data_t *vars, bool eof)
{
uint64_t max_vars = REQUEST_PARSE_BODY_OPTION_GET(max_input_vars, PG(max_input_vars));
Expand Down Expand Up @@ -536,57 +553,58 @@ SAPI_API SAPI_TREAT_DATA_FUNC(php_default_treat_data)

var = php_strtok_r(res, separator, &strtok_buf);

while (var) {
size_t val_len;
size_t new_val_len;

val = strchr(var, '=');

if (arg == PARSE_COOKIE) {
/* Remove leading spaces from cookie names, needed for multi-cookie header where ; can be followed by a space */
while (isspace(*var)) {
var++;
}
if (var == val || *var == '\0') {
goto next_cookie;
}
}

zend_long max_input_vars = REQUEST_PARSE_BODY_OPTION_GET(max_input_vars, PG(max_input_vars));
if (++count > max_input_vars) {
php_error_docref(NULL, E_WARNING, "Input variables exceeded " ZEND_LONG_FMT ". To increase the limit change max_input_vars in php.ini.", max_input_vars);
break;
}

if (val) { /* have a value */

*val++ = '\0';

if (arg == PARSE_COOKIE) {
val_len = php_raw_url_decode(val, strlen(val));
} else {
val_len = php_url_decode(val, strlen(val));
}
} else {
val = "";
val_len = 0;
}

val = estrndup(val, val_len);
if (arg != PARSE_COOKIE) {
php_url_decode(var, strlen(var));
}
if (sapi_module.input_filter(arg, var, &val, val_len, &new_val_len)) {
php_register_variable_safe(var, val, new_val_len, &array);
}
efree(val);
while (var) {
size_t val_len;
size_t new_val_len;

val = strchr(var, '=');

if (arg == PARSE_COOKIE) {
/* Remove leading spaces from cookie names, needed for multi-cookie header where ; can be followed by a space */
while (isspace(*var)) {
var++;
}
if (var == val || *var == '\0') {
goto next_cookie;
}
}

zend_long max_input_vars = REQUEST_PARSE_BODY_OPTION_GET(max_input_vars, PG(max_input_vars));
if (++count > max_input_vars) {
php_error_docref(NULL, E_WARNING, "Input variables exceeded " ZEND_LONG_FMT ". To increase the limit change max_input_vars in php.ini.", max_input_vars);
break;
}

if (val) { /* have a value */
*val++ = '\0';

if (arg == PARSE_COOKIE) {
val_len = php_raw_url_decode(val, strlen(val));
} else {
val_len = php_url_decode(val, strlen(val));
}
} else {
val = "";
val_len = 0;
}

val = estrndup(val, val_len);
if (arg != PARSE_COOKIE) {
php_url_decode(var, strlen(var));
}
php_sanitize_value(val, val_len);
val_len = strlen(val);
if (sapi_module.input_filter(arg, var, &val, val_len, &new_val_len)) {
php_register_variable_safe(var, val, new_val_len, &array);
}
efree(val);
next_cookie:
var = php_strtok_r(NULL, separator, &strtok_buf);
}

if (free_buffer) {
efree(res);
}
var = php_strtok_r(NULL, separator, &strtok_buf);
}
if (free_buffer) {
efree(res);
}
}

static zend_always_inline int valid_environment_name(const char *name, const char *end)
Expand Down
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