diff --git a/snappymail/v/0.0.0/app/libraries/snappymail/gpg/base.php b/snappymail/v/0.0.0/app/libraries/snappymail/gpg/base.php
index 64dd7f63d..e78ed81c0 100644
--- a/snappymail/v/0.0.0/app/libraries/snappymail/gpg/base.php
+++ b/snappymail/v/0.0.0/app/libraries/snappymail/gpg/base.php
@@ -487,7 +487,7 @@ abstract class Base
 
 	protected static function findBinary($name) : ?string
 	{
-		$binary = \function_exists('shell_exec') ? \trim((string) \shell_exec('which $name')) : '';
+		$binary = \function_exists('shell_exec') ? \trim((string) \shell_exec('which ' . \escapeshellarg($name))) : '';
 		if ($binary && \RainLoop\Utils::inOpenBasedir($binary) && \is_executable($binary)) {
 			return $binary;
 		}
diff --git a/snappymail/v/0.0.0/app/libraries/snappymail/gpg/pgp.php b/snappymail/v/0.0.0/app/libraries/snappymail/gpg/pgp.php
index f3921112f..30d9051f0 100644
--- a/snappymail/v/0.0.0/app/libraries/snappymail/gpg/pgp.php
+++ b/snappymail/v/0.0.0/app/libraries/snappymail/gpg/pgp.php
@@ -50,7 +50,7 @@ class PGP extends Base implements \SnappyMail\PGP\PGPInterface
 		// How to use gpgme-json ?
 		$this->binary = static::findBinary('gpg');
 
-		$info = \preg_replace('/\R +/', ' ', `$this->binary --with-colons --list-config`);
+		$info = \preg_replace('/\R +/', ' ', \shell_exec(\escapeshellcmd($this->binary) . ' --with-colons --list-config'));
 		if (\preg_match('/cfg:version:([0-9]+\\.[0-9]+\\.[0-9]+)/', $info, $match)) {
 			$this->version = $match[1];
 		}
diff --git a/snappymail/v/0.0.0/app/libraries/snappymail/gpg/smime.php b/snappymail/v/0.0.0/app/libraries/snappymail/gpg/smime.php
index 55a40301b..ec17fdd9e 100644
--- a/snappymail/v/0.0.0/app/libraries/snappymail/gpg/smime.php
+++ b/snappymail/v/0.0.0/app/libraries/snappymail/gpg/smime.php
@@ -43,7 +43,7 @@ class SMIME extends Base
 		// How to use gpgme-json ?
 		$this->binary = static::findBinary('gpgsm');
 
-		$info = \preg_replace('/\R +/', ' ', \shell_exec("{$this->binary} --version"));
+		$info = \preg_replace('/\R +/', ' ', \shell_exec(\escapeshellcmd($this->binary) . ' --version') );
 		if (\preg_match('/gpgsm.+([0-9]+\\.[0-9]+\\.[0-9]+)/', $info, $match)) {
 			$this->version = $match[1];
 		}