    public function testAltBodyAttachment()
    {
        $this->Mail->Body = 'This is the <strong>HTML</strong> part of the email.';
        $this->Mail->AltBody = 'This is the text part of the email.';
        $this->Mail->Subject .= ': AltBody + Attachment';
        $this->Mail->isHTML(true);

        if (!$this->Mail->addAttachment(__FILE__, 'test_attach.txt')) {
            self::assertTrue(false, $this->Mail->ErrorInfo);

            return;
        }

        //Test using non-existent UNC path
        self::assertFalse($this->Mail->addAttachment('\\\\nowhere\nothing'));

        $this->buildBody();
        self::assertTrue($this->Mail->send(), $this->Mail->ErrorInfo);
    }
The application deserializes untrusted data without sufficiently verifying that the resulting data will be valid.