ExpressionEngine versions 6.0.2 and below suffer from a Translate::save PHP code injection vulnerability.
ef038368400297010e360e1916e2d2fe----------------------------------------------------------------------------
ExpressionEngine <= 6.0.2 (Translate::save) PHP Code Injection
Vulnerability
----------------------------------------------------------------------------
[-] Software Link:
https://expressionengine.com/
[-] Affected Versions:
Version 6.0.2 and prior versions.
Version 5.4.1 and prior versions.
[-] Vulnerability Description:
The vulnerable code is located in the
"ExpressionEngine\Controller\Utilities\Translate::save()" method:
362. private function save($language, $file)
363. {
364.
365. $file = ee()->security->sanitize_filename($file);
366.
367. $dest_dir = $this->languages_dir . $language . '/';
368. $filename = $file . '_lang.php';
369. $dest_loc = $dest_dir . $filename;
370.
371. $str = '<?php' . "\n" . '$lang = array(' . "\n\n\n";
372.
373. ee()->lang->loadfile($file);
374.
375. foreach ($_POST as $key => $val) {
376. $val = str_replace('<script', '', $val);
377. $val = str_replace('<iframe', '', $val);
378. $val = str_replace(array("\\", "'"), array("\\\\",
"\'"), $val);
379.
380. $str .= '\'' . $key . '\' => ' . "\n" . '\'' . $val
. '\'' . ",\n\n";
381. }
382.
383. $str .= "''=>''\n);\n\n";
384. $str .= "// End of File";
[...]
400. $this->load->helper('file');
401.
402. if (write_file($dest_loc, $str)) {
403. ee('CP/Alert')->makeInline('shared-form')
404. ->asSuccess()
405. ->withTitle(lang('translations_saved'))
406. ->addToBody(sprintf(lang('file_saved'),
$dest_loc))
407. ->defer();
User input passed via keys of POST parameters is not properly sanitized
before being assigned
to the "$str" variable at line 380. Such a variable will be used in a
call to the "write_file()"
function at line 402, trying to write user supplied content into the
/system/user/language/[lang]/[file]_lang.php file. This can be exploited
to inject and execute arbitrary PHP code. Successful exploitation of
this vulnerability requires an account with
permissions to access the CP translation system utilities.
[-] Solution:
Upgrade to version 6.0.3, 5.4.2, or later.
[-] Disclosure Timeline:
[03/02/2021] - Vendor notified through HackerOne
[15/02/2021] - Vulnerability acknowledged by the vendor
[16/02/2021] - CVE number assigned
[17/02/2021] - Version 6.0.3 released
[04/03/2021] - Version 5.4.2 released
[15/03/2021] - Public disclosure
[-] CVE Reference:
The Common Vulnerabilities and Exposures project (cve.mitre.org)
has assigned the name CVE-2021-27230 to this vulnerability.
[-] Credits:
Vulnerability discovered by Egidio Romano.
[-] Other References:
https://hackerone.com/reports/1093444
[-] Original Advisory:
http://karmainsecurity.com/KIS-2021-03