How severe is CVE-2021-27220?

CVE-2021-27220 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2021-27220 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (79th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-27220?

CVE-2021-27220 affects Paessler Prtg Network Monitor. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-27220?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-27220 published?

CVE-2021-27220 was published on 2021-03-31 and last updated on 2026-06-17.

CVE-2021-27220

CVE-2021-27220 is a medium-severity vulnerability in Paessler Prtg Network Monitor with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v2: 5.0
EPSS exploit prediction: 2% (79th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Paessler Prtg Network Monitor
Published: 2021-03-31
Last modified: 2026-06-17

Description

An issue was discovered in PRTG Network Monitor before 21.1.66.1623. By invoking the screenshot functionality with prepared context paths, an attacker is able to verify the existence of certain files on the filesystem of the PRTG's Web server.

Frequently asked questions

What is CVE-2021-27220?: An issue was discovered in PRTG Network Monitor before 21.1.66.1623. By invoking the screenshot functionality with prepared context paths, an attacker is able to verify the existence of certain files on the filesystem of the PRTG's Web server.
How severe is CVE-2021-27220?: CVE-2021-27220 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2021-27220 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (79th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-27220?: CVE-2021-27220 affects Paessler Prtg Network Monitor. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-27220?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-27220 published?: CVE-2021-27220 was published on 2021-03-31 and last updated on 2026-06-17.

References

https://www.paessler.com/prtg/history/stable#21.1.66.1623

Affected products (1)

cpe:2.3:a:paessler:prtg_network_monitor:*:*:*:*:*:*:*:*

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