No One Drinks From the Firehose: How Organizations Filter and Prioritize Vulnerability Information

The number of published software vulnerabilities is increasing every year. How do organizations stay in control of their attack surface despite their limited staff resources? Prior work has analyzed the overall software vulnerability ecosystem as well as patching processes within organizations, but not how these two are connected. We investigate this missing link through semi-structured interviews with 22 organizations in critical infrastructure and government services. We analyse where in these organizations the responsibility is allocated to collect and triage information about software vulnerabilities, and find that none of our respondents is acquiring such information comprehensively, not even in a reduced and aggregated form like the National Vulnerability Database (NVD). This means that information on known vulnerabilities will be missed, even in critical infrastructure organizations. We observe that organizations apply implicit and explicit coping mechanisms to reduce their intake of vulnerability information, and identify three trade-offs in these strategies: independence, pro-activeness and formalization. Although our respondents’ behavior is in conflict with the widely accepted security advice to collect comprehensive vulnerability information about active systems, no respondents re- call having experienced a security incident that was associated with missing information on a known software vulnerability. This suggests that, given scarce resources, reducing the intake of vulnerability information by up to 95% can be considered a rational strategy. Our findings raise questions about the allocation of responsibility and accountability for finding vulnerable systems, as well as suggest changing expectations around collecting vulnerability information.