Any software with separate audio/video tracks on a timeline can adjust the audio/video synchronization. These include free programs like iMovie and Windows Movie Maker, as well as professional-grade suites, such as Adobe Premiere and Final Cut.
Since most completed movies will not have a clapboard or slate to pinpoint video frames for synchronization, you will need to find an appropriate point in the video for use. Navigate to the video frame of any sharp, distinctive sound, such as an object impact or hard spoken consonant.
Listen to the audio track to find the sound corresponding to the same moment in the video and drag the audio track to line up with the chosen video moment.
Depending on how the synch error occurred, you may only have to re-synchronize a section of the video. Watch the newly synchronized video in its entirety before export to ensure you have not created additional moments of unsynchronized playback.