XSS in PHP Event Calendar Project

CVE-2021-42078

PHP Event Calendar through 2021-11-04 allows persistent cross-site scripting (XSS), as demonstrated by the /server/ajax/events_manager.php title parameter. This can be exploited by an adversary in multiple ways, e.g., to perform actions on the page in the context of other users, or to deface the site.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.009 (55.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

  • cve@mitre.org (Exploit, Third Party Advisory, x_refsource_MISC)
  • cve@mitre.org (Exploit, Mailing List, Third Party Advisory, x_refsource_MISC)

Frequently asked questions

What is CVE-2021-42078?
CVE-2021-42078 is a medium-severity vulnerability in PHP Event Calendar Project, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2021-11-08.
How severe is CVE-2021-42078?
Medium severity. CVSS v3 base score is 6.1 out of 10.
Is CVE-2021-42078 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.