How severe is CVE-2020-20977?

CVE-2020-20977 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-2020-20977 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (39th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-20977?

CVE-2020-20977 affects Ukcms. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-20977?

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

When was CVE-2020-20977 published?

CVE-2020-20977 was published on 2021-08-12 and last updated on 2026-06-17.

CVE-2020-20977

CVE-2020-20977 is a medium-severity vulnerability in Ukcms 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% (39th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Ukcms
Published: 2021-08-12
Last modified: 2026-06-17

Description

A stored cross site scripting (XSS) vulnerability in index.php/legend/6.html of UK CMS v1.1.10 allows attackers to execute arbitrary web scripts or HTML via a crafted payload in the Comments section.

Frequently asked questions

What is CVE-2020-20977?: A stored cross site scripting (XSS) vulnerability in index.php/legend/6.html of UK CMS v1.1.10 allows attackers to execute arbitrary web scripts or HTML via a crafted payload in the Comments section.
How severe is CVE-2020-20977?: CVE-2020-20977 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-2020-20977 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (39th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-20977?: CVE-2020-20977 affects Ukcms. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-20977?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-20977 published?: CVE-2020-20977 was published on 2021-08-12 and last updated on 2026-06-17.

References

https://github.com/yxcmf/ukcms/issues/6

Affected products (1)

cpe:2.3:a:ukcms:ukcms:1.1.10:*:*:*:*:*:*:*

More vulnerabilities in Ukcms

CVE-2019-10888 — High (CVSS 8.8): A CSRF Issue that can add an admin user was discovered in UKcms v1.1.10 via admin.php/admin/role/add.html.
CVE-2018-14911 — High (CVSS 7.2): A file upload vulnerability exists in ukcms v1.1.7 and earlier. The vulnerability is due to the system not strictly…
CVE-2020-18449 — Medium (CVSS 5.4): Cross Site Scripting (XSS) vulnerability exists in UKCMS v1.1.10 via data in the index function in Single.php

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