When you post code or configuration, please add code tags. I added them for you this time.
DefaultSpringSecurityContextSource is part of spring-security-core, which is a dependency of spring-security-web.
Can you double-check whether Maven has downloaded spring-security-core to your local repository? Can you check whether this library contains the class that triggers the failure?
Another thing you can try is upgrading your spring security version. I noticed you're using Spring framework 4, but Spring security 3. It's a long shot, but you could try.
Actually, I took a look at the dependency graph, and you're referencing spring-security-taglib 4.0.2 and spring-security-web 3.2.3, which depend on conflicting versions of spring-security-core. I'm pretty sure that resolving the version conflict will fix your problem.
If you're not using it in your application, that's just a hack to fight symptoms. You should look at the underlying issue, which is that your dependency graph contains conflicts.