How severe is CVE-2021-29643?

CVE-2021-29643 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2021-29643 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (45th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-29643?

CVE-2021-29643 affects Paessler Prtg Network Monitor. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-29643?

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

When was CVE-2021-29643 published?

CVE-2021-29643 was published on 2021-09-13 and last updated on 2026-06-17.

CVE-2021-29643

CVE-2021-29643 is a medium-severity vulnerability in Paessler Prtg Network Monitor with a CVSS 3.x base score of 5.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: Medium (CVSS 3.x base score 5.4)
CVSS v2: 3.5
EPSS exploit prediction: 1% (45th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Paessler Prtg Network Monitor
Published: 2021-09-13
Last modified: 2026-06-17

Description

PRTG Network Monitor before 21.3.69.1333 allows stored XSS via an unsanitized string imported from a User Object in a connected Active Directory instance.

Frequently asked questions

What is CVE-2021-29643?: PRTG Network Monitor before 21.3.69.1333 allows stored XSS via an unsanitized string imported from a User Object in a connected Active Directory instance.
How severe is CVE-2021-29643?: CVE-2021-29643 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2021-29643 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (45th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-29643?: CVE-2021-29643 affects Paessler Prtg Network Monitor. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-29643?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-29643 published?: CVE-2021-29643 was published on 2021-09-13 and last updated on 2026-06-17.

References

Affected products (1)

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

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