Index: wp-admin/includes/class-wp-filesystem-ssh2.php
===================================================================
--- wp-admin/includes/class-wp-filesystem-ssh2.php	(revision 10446)
+++ wp-admin/includes/class-wp-filesystem-ssh2.php	(working copy)
@@ -217,6 +217,13 @@
 		return $ret;
 	}
 
+	function escape_dot($str) {
+		if (substr($str, 0, 1) != '/') # not an absolute path
+			$str = "./$str"; # assumes that "/" separates directories
+		$str = escapeshellarg($str);
+		return $str;
+	}
+
 	function cwd() {
 		$this->debug("cwd();");
 		$cwd = $this->run_command($this->link, 'pwd');
@@ -227,7 +234,7 @@
 
 	function chdir($dir) {
 		$this->debug("chdir();");
-		return $this->run_command($this->link, 'cd ' . $dir, true);
+		return $this->run_command($this->link, 'cd ' . escape_dot($dir), true);
 	}
 
 	function chgrp($file, $group, $recursive = false ) {
@@ -235,8 +242,8 @@
 		if ( ! $this->exists($file) )
 			return false;
 		if ( ! $recursive || ! $this->is_dir($file) )
-			return $this->run_command($this->link, sprintf('chgrp %o %s', $mode, $file), true);
-		return $this->run_command($this->link, sprintf('chgrp -R %o %s', $mode, $file), true);
+			return $this->run_command($this->link, sprintf('chgrp %o %s', $mode, escape_dot($file)), true);
+		return $this->run_command($this->link, sprintf('chgrp -R %o %s', $mode, escape_dot($file)), true);
 	}
 
 	function chmod($file, $mode = false, $recursive = false) {
@@ -248,8 +255,8 @@
 		if ( ! $this->exists($file) )
 			return false;
 		if ( ! $recursive || ! $this->is_dir($file) )
-			return $this->run_command($this->link, sprintf('chmod %o %s', $mode, $file), true);
-		return $this->run_command($this->link, sprintf('chmod -R %o %s', $mode, $file), true);
+			return $this->run_command($this->link, sprintf('chmod %o %s', $mode, escape_dot($file)), true);
+		return $this->run_command($this->link, sprintf('chmod -R %o %s', $mode, escape_dot($file)), true);
 	}
 
 	function chown($file, $owner, $recursive = false ) {
@@ -257,8 +264,8 @@
 		if ( ! $this->exists($file) )
 			return false;
 		if ( ! $recursive || ! $this->is_dir($file) )
-			return $this->run_command($this->link, sprintf('chown %o %s', $mode, $file), true);
-		return $this->run_command($this->link, sprintf('chown -R %o %s', $mode, $file), true);
+			return $this->run_command($this->link, sprintf('chown %o %s', $mode, escape_dot($file)), true);
+		return $this->run_command($this->link, sprintf('chown -R %o %s', $mode, escape_dot($file)), true);
 	}
 
 	function owner($file) {
@@ -311,13 +318,13 @@
 
 	function exists($file) {
 		$this->debug("exists();");
-		return $this->run_command($this->link, sprintf('ls -lad %s', $file), true);
+		return $this->run_command($this->link, sprintf('ls -lad %s', escape_dot($file)), true);
 	}
 
 	function is_file($file) {
 		$this->debug("is_file();");
 		//DO NOT RELY ON dirlist()!
-		$list = $this->run_command($this->link, sprintf('ls -lad %s', $file));
+		$list = $this->run_command($this->link, sprintf('ls -lad %s', escape_dot($file)));
 		$list = $this->parselisting($list);
 		if ( ! $list )
 			return false;
@@ -328,7 +335,8 @@
 	function is_dir($path) {
 		$this->debug("is_dir();");
 		//DO NOT RELY ON dirlist()!
-		$list = $this->parselisting($this->run_command($this->link, sprintf('ls -lad %s', untrailingslashit($path))));
+		$list = $this->parselisting($this->run_command($this->link, sprintf('ls -lad %s',
+                                                               escape_dot(untrailingslashit($path)))));
 		if ( ! $list )
 			return false;
 		else
@@ -448,7 +456,7 @@
 			$limitFile = false;
 		}
 
-		$list = $this->run_command($this->link, sprintf('ls -la %s', $path));
+		$list = $this->run_command($this->link, sprintf('ls -la %s', escape_dot($path)));
 
 		if ( $list === false )
 			return false;