This is not an issue, as the widgets in the footer don’t go further than the sidebar anyway.
I have just checked and #23504 is about this issue. Check it out!
Like I said it shouldn’t be a problem in most cases… but it does not look very nice. And using dark letters the sidebar menu becomes unreadable.
Sorry, not unreadable as the widgets have a light colored background…
hope this thing will helps . open the content.php
<article id="post-<?php the_ID(); ?>" <?php post_class(); ?> style="<?php if ( is_single() ) { ?>min-height:1150px<?php } ?>">
change the minimum height manually according to the height of your sidebar