CVE-2021-24503

CVE-2021-24503 is a medium-severity vulnerability in Thememason Popular Brand Icons - Simple Icons 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

Description

The Popular Brand Icons – Simple Icons WordPress plugin before 2.7.8 does not sanitise or validate some of its shortcode parameters, such as "color", "size" or "class", allowing users with a role as low as Contributor to set Cross-Site payload in them. A post made by a contributor would still have to be approved by an admin to have the XSS triggered in the frontend, however, higher privilege users, such as editor could exploit this without the need of approval, and even when the blog disallows the unfiltered_html capability.

Frequently asked questions

What is CVE-2021-24503?
The Popular Brand Icons – Simple Icons WordPress plugin before 2.7.8 does not sanitise or validate some of its shortcode parameters, such as "color", "size" or "class", allowing users with a role as low as Contributor to set Cross-Site payload in them. A post made by a contributor would still have to be approved by an admin to have the XSS triggered in the frontend, however, higher privilege users, such as editor could exploit this without the need of approval, and even when the blog disallows the unfiltered_html capability.
How severe is CVE-2021-24503?
CVE-2021-24503 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-2021-24503 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-24503?
CVE-2021-24503 affects Thememason Popular Brand Icons - Simple Icons. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-24503?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-24503 published?
CVE-2021-24503 was published on 2021-08-02 and last updated on 2026-06-17.

References

Affected products (1)

Other CWE-79 (Cross-site Scripting (XSS)) vulnerabilities

Browse all CWE-79 (Cross-site Scripting (XSS)) vulnerabilities →