MTTR and verified remediation: where patch programs really stall

TL;DR: Reducing MTTR requires shrinking the time spent detecting, triaging, testing and deploying fixes, according to Action1's guide, because the clock should stop only when remediation is verified and exposure is actually closed. Faster deployment helps, but verification, coverage and workflow bottlenecks determine whether risk really falls.

Editorial analysis by NHI Mgmt Group, based on content published by Action1: “How to Reduce MTTR: A Practical Guide for Patching, Vulnerability Remediation, and Software Incidents”.

By the numbers:

• Teams take an average of 54.8 days to remediate high- and critical-severity device and network vulnerabilities in Edgescan's dataset, according to Action1.
• High- and critical-severity application and API vulnerabilities take an average of 74.3 days to fix in Edgescan's dataset, according to Action1.
• Mandiant found that average time to exploit fell from 63 days in 2018-19 to just 5 days in 2023, according to Action1.

Key questions

Q: What breaks when remediation is measured only at deployment time?

A: You lose sight of the systems that are still exposed after the rollout finishes.

Q: Why do slow remediation cycles increase security risk so quickly?

A: Because the exposure window stays open for as long as a known vulnerability remains reachable.

Q: How do security teams know whether MTTR is actually improving?

A: MTTR is improving only if faster closure also reduces reopen rates, shortens verification time, and lowers the number of unresolved high-severity items.

Practitioner guidance

• Define a single remediation clock Choose one start point for vulnerability work, such as public disclosure or first internal detection, and one end point, such as verified closure on every in-scope asset.
• Separate detection, acknowledgement and remediation metrics Track MTTD, MTTA and MTTR independently so the team can see whether delays are caused by discovery, queueing or execution.
• Require verified closure before ticket completion Keep a remediation item open until the fix is confirmed on each affected endpoint or the remaining risk is formally accepted under policy.

Bottom line: MTTR only becomes a useful security measure when the organisation defines a single start point and closes the loop with verified remediation.

Explore further

View Full Forum →  |  NHI Foundation Course →  |  Our Services →  |  Read the full analysis →