CrowdStrike is blaming a bug in an update that allowed its cybersecurity systems to push bad data out to millions of customer computers, setting off last week’s global tech outage that grounded flights, took TV broadcasts off air and disrupted banks, hospitals and retailers. CrowdStrike also outlined measures it would take to prevent the problem from recurring, including staggering the rollout of updates, giving customers more control over when and where they occur, and providing more details about the updates that it plans. The company on Wednesday posted details online from its “preliminary post incident review ” of the outage, which caused chaos for the many businesses that pay for the cybersecurity firm’s software services. The problem involved an “undetected error” in the content configuration update for its Falcon platform affecting Windows machines, the Texas company said. A bug in the content validation system allowed “problematic content data” to be deployed to CrowdStrike’s customers.