Most of your clients probably believe their systems are patched and protected. Yet every week, new vulnerabilities appear that could give attackers access to those same “protected” systems.
When a new vulnerability is discovered, you have an average of just five days before attackers begin exploiting it — down from 32 days in previous years (more on that later in this post). Adding continuous vulnerability management to your security services lets you spot and fix these weaknesses before attackers get their chance.
But how do you determine which vulnerabilities demand immediate action and which can wait? This strategic risk prioritization marks the difference between proactive security and constant firefighting.
Before exploring interpretation strategies, let's establish two fundamental concepts in vulnerability scanning for MSPs:
A zero-day vulnerability represents a security flaw that attackers exploit before vendors or security teams discover it exists. The term "zero-day" refers to defenders having zero days to prepare or protect against it.
An n-day vulnerability refers to any security flaw that has been publicly known for 'n' number of days. While patches typically exist for these vulnerabilities, systems remain at risk until updates are applied.
Recent data underscores why these definitions matter. Google's 2023 analysis reveals that 70% of analyzed vulnerabilities were exploited as zero-days, while the average Time-to-Exploit (TTE) for n-day vulnerabilities dropped to just five days — down from 32 days in previous years. For MSPs, this dramatic reduction means the time available to assess and patch vulnerabilities has shrunk significantly.
Vulnerability scanning falls into two distinct categories, each serving different security objectives:
External vulnerability scanning focuses on the attack surface that is exposed to the outside world — the internet-facing assets visible to potential attackers. This includes web servers, email gateways, remote access points, and cloud services. External scans identify vulnerabilities in your clients' digital perimeter, where most initial breach attempts occur.
Comprehensive vulnerability scanning encompasses both external and internal systems. This includes workstations, internal servers, network devices, and applications that may not directly connect to the internet but could be targeted once an attacker gains initial access.
The distinction matters for prioritization. When a critical vulnerability appears in an internet-facing system, the exposure risk multiplies. IBM's 2024 Cost of a Data Breach Report found that breaches involving public cloud assets cost organizations an average of $5.17 million — highlighting why external vulnerabilities often demand faster response.
However, internal systems require equal attention in your security strategy. Attackers who breach the perimeter will probe for internal vulnerabilities, making regular comprehensive scanning essential for defense in depth.
MSPs need reliable metrics to evaluate vulnerability severity. Two key scoring systems work together to inform prioritization decisions:
CVSS assigns a base score from 0-10 to vulnerabilities based on their inherent characteristics:
While CVSS helps understand a vulnerability's potential impact, it doesn't indicate the likelihood of exploitation.
EPSS fills this gap by predicting the probability that a vulnerability will be exploited in the wild. Recent analysis from Cyentia Institute and FIRST revealed:
Using these systems together provides a clearer picture. CVSS tells you how severe a vulnerability could be, while EPSS indicates how likely it is to be targeted. For example, a vulnerability with a high CVSS score but low EPSS score might be less urgent than one with moderate CVSS but high EPSS.
Read more: EPSS Scoring: A Quick Guide for MSPs on Vulnerability Prioritization
Raw vulnerability scores don't tell the complete story. Consider these factors when assessing scan results:
The shrinking exploit timeline demands swift action. With a Time-to-Exploit of just five days, it’s important to keep in mind:
Not every vulnerability demands an immediate patch. Consider:
The presence of strong compensating controls might allow you to address some vulnerabilities during scheduled maintenance instead of emergency patching.
Establish clear remediation timelines based on risk levels:
Critical Risks (Address within 24-48 hours):
High Risks (Address within one week):
Medium Risks (Address within 30 days):
Prevention is far more cost-effective than dealing with a breach. Streamline your vulnerability management through:
This approach helps identify and address vulnerabilities before they can be exploited, reducing the risk of breaches occurring in the first place.
Keep clients informed without causing alarm:
Effective vulnerability management requires balancing speed, precision, and resources. Understanding the relationship between zero-day and n-day vulnerabilities, utilizing both CVSS and EPSS scoring systems, and maintaining clear communication with clients creates a foundation for success. As exploitation timelines continue to shrink MSPs must evolve their approach to vulnerability assessment and remediation.
Start protecting your clients' digital perimeter today with ConnectSecure's comprehensive vulnerability scanning platform. Sign up for a 14-day free trial to experience:
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