Zero-day vulnerabilities remain one of the major security threats that are faced by organizations. Once a vendor learns about a zero-day vulnerability, releasing a timely patch becomes a priority given the risk of zero-day exploits. However, we still lack information on the factors that affect patch release time of such vulnerabilities. The main objective of this study is to examine the impact of other as-yet unexplored factors on the patch release time of zero-day vulnerabilities. Using zero-day vulnerability dataset captured between 2010 and 2020, we employ survival analysis technique. Our model explores the impact of vulnerability attack vector, attack complexity, privileges required, user interaction, scope, confidentiality, integrity, and availability impact on patch release timing. Findings show that a zero-day vulnerability is more likely to be patched on time if the vulnerability results in a scope change and affects more vendors, products, and versions. However, a zero-day vulnerability is less likely to be patched on time if it requires privileges and impacts confidentiality. Our sub-analyses also reveal how patch release times vary across different products and vulnerability types.

With the increasing number and severity of security incidents and exploits, information technology (IT) vendors, security managers, and consumers have begun to place more emphasis on security. Yet, fixing the sheer volume of vulnerabilities remains a challenge as IT vendors race against attackers to evaluate system vulnerabilities, prioritize them, and issue security patches before cybercriminals can exploit them. In this study, we posit that IT vendors can prioritize which vulnerabilities they should patch first by assessing their exploitability risk. Accordingly, we identified the vulnerabilities that cybercriminals will most likely exploit using vulnerability-related attributes and vulnerability types. To do so, we employed survival analysis and tested our models using historical data of vulnerabilities and exploits between 2007 and 2016. Our results indicate that IT vendors benefit the most from fixing remotely exploitable vulnerabilities; non-complex vulnerabilities; vulnerabilities that require no authentication; and vulnerabilities that affect confidentiality, integrity, and availability components. Furthermore, our findings suggest that IT vendors can mitigate the risk of exploit-related attacks by remedying code-injection vulnerabilities, buffer-overflow vulnerabilities, and numeric-error vulnerabilities.