The document discusses metrics for prioritizing security efforts. It proposes using attack surfaces, which are all paths for data and commands in software, to identify code most likely to have vulnerabilities. The approach analyzes crash dump stack traces to determine which code is involved in crashes, representing active parts of the attack surface. Analysis of Windows, Firefox, and Fedora crashes found this approach covered the majority of known vulnerabilities. Undergraduate research further classified vulnerability types covered and visualized the data. The approach was found to outperform alternative models using software metrics or text mining alone or in combination.