Autodesk has released AutoCAD 2013 SP 1.1.
Autodesk released Service Pack 1 for AutoCAD 2013 and AutoCAD LT 2013 on Aug 18, 2012. They pulled the service Pack a few days later.
On Sept 7, 2012 they released an incremental version aptly named SP 1.1.
AutoCAD Only Almost
WARNING - The AutoCAD 2013 SP1.1 Update page currently states the Service Pack can be applied to Infrastructure Design Suite products.
This is an ERROR unless you have ONLY installed AutoCAD 2013 from the Suite.
This service pack is NOT listed on the AutoCAD Civil 3D or AutoCAD Map 3D 2013 Updates pages.
DO NOT install on AutoCAD Civil 3D or AutoCAD Map installations
This service pack should NOT be applied to AutoCAD 2013 vertical Design Suite products except as specifically noted on the AutoCAD 2013 SP1.1 Updates page.
This includes AutoCAD Map 3D 2013 and AutoCAD Civil 3D 2013.
Vertical version Service Packs that include this ACAD service pack will be released at a later date.
The service pack fixes many mostly minor issues (see the readme).
AutoCAD 2013 SP1.1 also adds new anti-malware drawing variables to AutoCAD 2013 drawings.
Here's the link to the AutoCAD 2013 Updates page
To read more about the new anti-malware drawing variables visit this post on Without a Net.