CVE-2021-40542

CVE-2021-40542 is a medium-severity vulnerability in Os4ed Opensis 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

Description

Opensis-Classic Version 8.0 is affected by cross-site scripting (XSS). An unauthenticated user can inject and execute JavaScript code through the link_url parameter in Ajax_url_encode.php.

Frequently asked questions

What is CVE-2021-40542?
Opensis-Classic Version 8.0 is affected by cross-site scripting (XSS). An unauthenticated user can inject and execute JavaScript code through the link_url parameter in Ajax_url_encode.php.
How severe is CVE-2021-40542?
CVE-2021-40542 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-2021-40542 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (86th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-40542?
CVE-2021-40542 affects Os4ed Opensis. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-40542?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-40542 published?
CVE-2021-40542 was published on 2021-10-11 and last updated on 2026-06-17.

References

Affected products (1)

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