The vBulletin team released patches for a security exploit that affected all versions of vBulletin including 3.5, 3.6, 3.7, 3.8, 4.X, 5.X.
A security issue has been found that affects all versions of vBulletin including 3.x, 4.x and 5.x. We have released security patches to account for this vulnerability. This includes patches for vBulletin 3.8.7, vBulletin 4.2.2 and all versions of vBulletin 5 (including Cloud accounts). The patch is also applied to vBulletin 5.1.0 RC1. It is imperative that you apply these patches as soon as possible.
Install the patch provided by vBulletin team (consult web references for a dirrect link to this patch).