What is CVE-2021-39320?

CVE-2021-39320 is a medium-severity vulnerability in Noah Kagan Underconstruction, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2021-09-01.

How severe is CVE-2021-39320?

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

Is CVE-2021-39320 known to be exploited?

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

XSS in Noah Kagan Underconstruction

CVE-2021-39320

The underConstruction plugin <= 1.18 for WordPress echoes out the raw value of `$GLOBALS['PHP_SELF']` in the ucOptions.php file. On certain configurations including Apache+modPHP, this makes it possible to use it to perform a reflected Cross-Site Scripting attack by injecting malicious code in the request path.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.023 (81.7th 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

Noah Kagan Underconstruction — versions 1.18
Underconstruction_project Underconstruction

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

Public proof-of-concept exploits

References

security@wordfence.com (Third Party Advisory, x_refsource_MISC)
security@wordfence.com (Third Party Advisory, x_refsource_MISC)

Frequently asked questions

What is CVE-2021-39320?: CVE-2021-39320 is a medium-severity vulnerability in Noah Kagan Underconstruction, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2021-09-01.
How severe is CVE-2021-39320?: Medium severity. CVSS v3 base score is 6.1 out of 10.
Is CVE-2021-39320 known to be exploited?: 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.