Badlock - Definition from theHotspot Shield Glossary
Badlock is an online security bug that affects the SAM (Security Account Manager) and LSAD (Local Security Authority Domain Policy) protocols that are supported by both Samba and Windows servers. The two protocols SAM and LSAD are implemented as part of the DCE/RPC protocol that is used in all Windows and Samba servers.
These services allowed the attackers to execute a Man in the middle attack and also DoS attacks - Man in the middle attacks can be used to intercept network traffic and view sensitive network data while DoS attacks will generally slow down the server performance. Both Microsoft and Samba developers released patches for their software and urged users to update their server versions urgently.