What is CVE-2021-20815?

CVE-2021-20815 is a medium-severity vulnerability in Sixapart Movable_type, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2021-08-26.

How severe is CVE-2021-20815?

Medium severity. CVSS v3 base score is 6.1 out of 10.

Is CVE-2021-20815 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

XSS in Sixapart Movable_type

CVE-2021-20815

Cross-site scripting vulnerability in Edit Boilerplate screen of Movable Type (Movable Type 7 r.4903 and earlier (Movable Type 7 Series), Movable Type 6.8.0 and earlier (Movable Type 6 Series), Movable Type Advanced 7 r.4903 and earlier (M…

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.009 (55.7th 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

Sixapart Movable_type
Six Apart Ltd. Movable Type — versions Movable Type 7 r.4903 and earlier (Movable Type 7 Series), Movable Type 6.8.0 and earlier (Movable Type 6 Series), Movable Type Advanced 7 r.4903 and earlier (Movable Type Advanced 7 Series), Movable Type Premium 1.44 and earlier, and Movable Type Premium Advanced 1.44 and earlier

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

Public proof-of-concept exploits

n0-traces/cve_

References

vultures@jpcert.or.jp (x_refsource_MISC, Release Notes, Vendor Advisory)
vultures@jpcert.or.jp (Third Party Advisory, x_refsource_MISC)

Frequently asked questions

What is CVE-2021-20815?: CVE-2021-20815 is a medium-severity vulnerability in Sixapart Movable_type, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2021-08-26.
How severe is CVE-2021-20815?: Medium severity. CVSS v3 base score is 6.1 out of 10.
Is CVE-2021-20815 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.