Security Updates: What a Security Update is and Why Delaying It May be Costly

According to Verizon’s 2024 Data Breach Investigations Report, exploitation of vulnerabilities as an initial access vector nearly tripled year over year. The pattern behind that spike wasn’t sophisticated zero-day attacks. It was businesses leaving known, already-patched vulnerabilities unaddressed long enough for attackers to use them.

Publishing a security patch documents the underlying vulnerability for everyone at the same moment: defenders who need to apply it and attackers who want to exploit it first. The risk window opens when the update ships, not when an attacker independently discovers the flaw.

This article covers:

• What security updates actually fix at the code level
• How fast attackers move once a patch is public
• What delayed patching costs businesses that find out too late

What a Security Update Actually Does

A security update delivers a targeted code change that closes a specific, documented software flaw. It does not add features, change the user interface, or alter how the software behaves in daily use. From your team’s perspective, nothing looks different after the update runs. From an attacker’s perspective, a documented entry point has been removed.

Most patches address Common Vulnerabilities and Exposures (CVEs): publicly catalogued weaknesses scored by severity using the Common Vulnerability Scoring System (CVSS). CVSS scores range from Low to Critical. A Critical rating, scored 9.0 or above, indicates a flaw that attackers can exploit remotely with no user interaction required.

Patches target every layer of your technology stack:

• Operating systems and server software
• Applications, browsers, and email clients
• Firmware and device drivers

Attackers don’t care which layer they use. They exploit whichever one is weakest.

The full context around what a software patch is and why it matters covers the patch lifecycle in depth. This article focuses on what happens when the update doesn’t get applied quickly enough.

Security Updates vs. Feature Updates: Not the Same Thing

These two update types serve entirely different purposes. The urgency behind each reflects that gap.

Feature updates add new capabilities, interface changes, or platform improvements. Delaying one for compatibility testing is a reasonable IT practice.

Security updates exist solely to close known attack vectors. Delaying one for the same reason requires a documented risk-acceptance process and a compensating control in place during the gap. “We’ll handle it next maintenance window” does not qualify as either.

Windows separates these categories cleanly, publishing security patches on a predictable monthly schedule distinct from feature releases. On mobile platforms including Android, monthly security patches and feature improvements are often bundled in the same release, which makes holding an update back a riskier decision than it appears.

When a vendor emails about “the new security update,” that phrase almost always signals a newly disclosed CVE has been addressed, not a product improvement. The clock starts running the moment that notification arrives.

What Happens When You Skip a Security Update

Skipped updates don’t disappear from your risk profile. Each one is a documented, scoreable vulnerability sitting on your network, and threat actors actively scan for exactly these gaps.

• Known vulnerabilities are low-effort targets. Attackers don’t need zero-days when published CVEs go unaddressed for weeks. Unpatched systems are the path of least resistance.
• Ransomware operators scan for unpatched endpoints. WannaCry and NotPetya both exploited EternalBlue (MS17-010), a Windows flaw with a patch available weeks before either attack launched. The patch existed. The patching at scale did not.
• Deferred patches compound. Each skipped update adds another exposure layer. Remediation after a breach costs far more than the brief maintenance window the update would have required.
• Compliance frameworks mandate documented patching cadences. The Health Insurance Portability and Accountability Act (HIPAA), Payment Card Industry Data Security Standard (PCI DSS), and the Federal Trade Commission (FTC) Safeguards Rule all require patch management processes. Undocumented gaps create audit findings and regulatory exposure.
• Cyber insurance carriers are denying claims when post-breach forensics show a known patch was available and not applied. This is an active underwriting reality, not a future hypothetical.

If your current patching cadence can’t keep pace with how quickly CVEs are weaponized, that gap will show up in your compliance posture, your insurance coverage, or both. Chicago cybersecurity services that include proactive patch management give organizations a significantly stronger foundation than reactive internal processes do.

The Exploit Timeline: How Fast Attackers Move After a Patch Drops

The urgency behind security updates becomes concrete when you map what happens in the hours and days after a vendor publishes a fix.

1. Patch published. The vendor releases the fix alongside the CVE record. The vulnerability is now public knowledge for defenders and attackers simultaneously.
2. Reverse engineering begins (hours to 72 hours). Security researchers and threat actors analyze the patch to identify the underlying flaw. Proof-of-concept exploit code frequently surfaces within three days of publication.
3. Exploit code circulates (days 3-7). Working exploit code spreads on dark web forums and gets incorporated into commercial exploit kits available to lower-skilled attackers.
4. Automated scanning begins (week one to two). Scanners sweep the public internet for unpatched systems, building target lists for ransomware and data-exfiltration campaigns.
5. Unpatched businesses become active targets. At this point, “I was going to get to it” becomes an incident response conversation, not an IT planning one.

The EternalBlue timeline makes this real. Microsoft released the MS17-010 patch in March 2017. WannaCry launched in May 2017, roughly 59 days later, using that unpatched flaw to take down hospitals and logistics firms globally. The vulnerability was documented and the patch was available. Widespread deployment never followed.

How Often Should You Install Security Updates?

The practical answer: Critical and High-severity patches should not sit in the queue until the next scheduled maintenance window three weeks out.

The Cybersecurity and Infrastructure Security Agency (CISA) Known Exploited Vulnerabilities catalog sets a two-week remediation requirement for actively exploited vulnerabilities. For private businesses, it’s a well-grounded benchmark that reflects how quickly weaponization follows public disclosure.

Patch cadence by system type:

• Critical and High-severity patches: Apply as soon as possible after a brief compatibility check, not during the next scheduled window.
• Windows and server operating systems: Follow the monthly Patch Tuesday cadence as your baseline. Out-of-band emergency patches signal active exploitation and warrant immediate deployment.
• Browsers and productivity apps: Email clients, PDF readers, and office software rank among the most frequently exploited attack vectors. Enable auto-updates where your business environment permits.
• Mobile devices: Android patch availability varies by manufacturer and carrier, creating deployment gaps in business device fleets. iOS updates are more uniform but still require mobile device management (MDM) policy enforcement to ensure they actually deploy across company-owned devices.

One rule applies across all systems: out-of-band patches released outside the normal monthly cycle always signal active exploitation in the wild. Treat them as the highest-priority deployment on your team’s schedule regardless of what else is queued.

Managing Software Updates Across a Business: Where It Gets Hard

A 50-person company runs 100 or more endpoints across desktops, laptops, servers, and mobile devices. Each requires individual patch visibility, deployment tracking, and documentation. A lean internal IT team can’t realistically maintain that level of tracking alongside everything else on its plate.

Patches need testing before broad deployment to avoid breaking dependent applications. A proper testing stage requires:

• Process infrastructure to stage and validate updates before rollout
• Documented escalation paths for urgent out-of-band patches
• Tracking systems to confirm deployment across every endpoint

Most internal teams don’t have the bandwidth to build and sustain all three consistently.

Without a formal patch management system, patching becomes reactive. The gap surfaces after a breach, not before it, and the remediation cost reflects that timeline.

For businesses across the Chicago area, working with a managed IT services provider covers all of that without requiring you to build it internally. Automated patch deployment, device-level compliance tracking, and emergency patch handling are included. The cost of reacting after a breach always exceeds the cost of managing patches proactively.

Patching as a System, Not an Afterthought

When patching runs on a documented schedule and high-severity vulnerabilities get addressed within days rather than weeks, your business doesn’t scramble after a breach notification. Compliance audits don’t surface gaps tied to missed update cycles. Ransomware operators find your systems patched instead of a documented CVE sitting unaddressed in your environment.

LeadingIT provides managed IT and cybersecurity services to businesses across the Chicagoland area, including automated patch management, endpoint protection, 24/7 monitoring, and compliance documentation support. We track and deploy patches across your entire device fleet, handle out-of-band emergency releases without waiting for the next scheduled window, and produce the documentation your auditors and insurers need.

Talk to LeadingIT about Chicago cybersecurity services or call 815-788-6041 to discuss where your current patch management process stands and what it would take to close the gaps.