How severe is CVE-2017-9781?

CVE-2017-9781 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2017-9781 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (72nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2017-9781?

CVE-2017-9781 primarily affects Check Mk Project Check Mk. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2017-9781?

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

When was CVE-2017-9781 published?

CVE-2017-9781 was published on 2017-06-21 and last updated on 2026-06-17.

CVE-2017-9781

CVE-2017-9781 is a medium-severity vulnerability in Check Mk Project Check Mk with a CVSS 3.x base score of 6.1. 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 6.1)
CVSS v2: 4.3
EPSS exploit prediction: 2% (72nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Check Mk Project Check Mk
Published: 2017-06-21
Last modified: 2026-06-17

Description

A cross site scripting (XSS) vulnerability exists in Check_MK versions 1.4.0x prior to 1.4.0p6, allowing an unauthenticated remote attacker to inject arbitrary HTML or JavaScript via the _username parameter when attempting authentication to webapi.py, which is returned unencoded with content type text/html.

Frequently asked questions

What is CVE-2017-9781?: A cross site scripting (XSS) vulnerability exists in Check_MK versions 1.4.0x prior to 1.4.0p6, allowing an unauthenticated remote attacker to inject arbitrary HTML or JavaScript via the _username parameter when attempting authentication to webapi.py, which is returned unencoded with content type text/html.
How severe is CVE-2017-9781?: CVE-2017-9781 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2017-9781 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (72nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2017-9781?: CVE-2017-9781 primarily affects Check Mk Project Check Mk. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2017-9781?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2017-9781 published?: CVE-2017-9781 was published on 2017-06-21 and last updated on 2026-06-17.

References

Affected products (6)

cpe:2.3:a:check_mk_project:check_mk:1.4.0:*:*:*:*:*:*:*
cpe:2.3:a:check_mk_project:check_mk:1.4.0:p1:*:*:*:*:*:*
cpe:2.3:a:check_mk_project:check_mk:1.4.0:p2:*:*:*:*:*:*
cpe:2.3:a:check_mk_project:check_mk:1.4.0:p3:*:*:*:*:*:*
cpe:2.3:a:check_mk_project:check_mk:1.4.0:p4:*:*:*:*:*:*
cpe:2.3:a:check_mk_project:check_mk:1.4.0:p5:*:*:*:*:*:*

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