CVE-2021-34667

CVE-2021-34667 is a medium-severity vulnerability in Calendar Plugin Project Calendar Plugin 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

The Calendar_plugin WordPress plugin is vulnerable to Reflected Cross-Site Scripting due to the use of `$_SERVER['PHP_SELF']` in the ~/calendar.php file which allows attackers to inject arbitrary web scripts, in versions up to and including 1.0.

Frequently asked questions

What is CVE-2021-34667?
The Calendar_plugin WordPress plugin is vulnerable to Reflected Cross-Site Scripting due to the use of `$_SERVER['PHP_SELF']` in the ~/calendar.php file which allows attackers to inject arbitrary web scripts, in versions up to and including 1.0.
How severe is CVE-2021-34667?
CVE-2021-34667 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-2021-34667 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (55th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-34667?
CVE-2021-34667 affects Calendar Plugin Project Calendar Plugin. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-34667?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-34667 published?
CVE-2021-34667 was published on 2021-08-16 and last updated on 2026-06-17.

References

Affected products (1)

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