Evidence-based cybersecurity policy? A meta-review of security control effectiveness

Cybersecurity policy should guide firms towards implementing the most effective security controls and procedures. However, there is no authority that collects evidence and ranks cybersecurity controls by efficacy. The evidence needed by policymakers is distributed across academic studies and industry white papers. To address this gap, we conduct a meta-review of studies that empirically evaluate the efficacy of cybersecurity interventions. Attack surface management and patch cadence were consistently the first and second most effective interventions. Reduced cyber insurance claims frequency was associated with migrating to cloud email and avoiding specific VPN providers. Multi-factor authentication was effective in protecting individual accounts, although inconsistent MFA-implementation undermines efficacy when rolled out across an organisation. The evidence suggests effectiveness is driven by how a control is implemented more than by a binary yes-no regarding whether it is implemented. Thus, policy measures that mandate specific controls are unlikely to result in risk reduction. Instead, policymakers should aim to support organisations in administering security controls and making risk-based decisions. Successful examples can be seen in policy measures that improve the efficiency of patch management, such as funding for the US National Vulnerability Database, CERT/CC, and the Known Exploited Vulnerabilities catalog.