XSS in Hendrik Erz Zettlr

CVE-2021-20727

Cross-site scripting vulnerability in Zettlr from 0.20.0 to 1.8.8 allows an attacker to execute an arbitrary script by loading a file or code snippet containing an invalid iframe into Zettlr.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.010 (61.0th 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

Frequently asked questions

What is CVE-2021-20727?
CVE-2021-20727 is a medium-severity vulnerability in Hendrik Erz Zettlr, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2021-05-27.
How severe is CVE-2021-20727?
Medium severity. CVSS v3 base score is 6.1 out of 10.
Is CVE-2021-20727 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.