CVE-2021-38320: The simpleSAMLphp Authentication WordPress plugin is vulnerable to Reflected Cross-Site Scripting due to a ref

Q: How do I fix CVE-2021-38320?

simplesamlphp authentication: upgrade to newer than 0.7.0. Exact commands for each OS are on this page.

Q: Is CVE-2021-38320 being exploited?

CVE-2021-38320 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2021-38320 affect?

CVE-2021-38320 affects simplesamlphp authentication. Severity is medium (CVSS 6.1). The simpleSAMLphp Authentication WordPress plugin is vulnerable to Reflected Cross-Site Scripting due to a reflected $_SERVER["PHP_SELF"] value in the ~/simplesamlphp-authentication.php file which allows attackers to inject arbitrary web sc

Q: How urgent is CVE-2021-38320?

Priority 42/100. Public exploit reference

This month

MEDIUM 6.1UPGRADE

CVE-2021-38320 is a medium-severity flaw (CVSS 6.1) affecting simplesamlphp authentication. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The simpleSAMLphp Authentication WordPress plugin is vulnerable to Reflected Cross-Site Scripting due to a reflected $_SERVER["PHP_SELF"] value in the ~/simplesamlphp-authentication.php file which allows attackers to inject arbitrary web scripts, in versions up to and including 0.7.0.

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	6.1 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	1.0% (top 38%)
CISA exploited list	No
Weakness	CWE-79
Published	2021-09-09
Last modified	2026-06-17

Publisher (CNA): Wordfence · Vendor: simplesamlphp authentication project

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-09-09 19:15 UTCPublished CVE record published
2026-06-17 04:01 UTCUpdated Record last modified

simplesamlphp authentication project simplesamlphp authentication UPGRADE

Affected: <= 0.7.0

Fixed in: newer than 0.7.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy simplesamlphp-authentication || rpm -q simplesamlphp-authentication || simplesamlphp-authentication --version

2. UPGRADE to newer than 0.7.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade simplesamlphp-authentication

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade simplesamlphp-authentication

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2021-38320?

simplesamlphp authentication: upgrade to newer than 0.7.0. Exact commands for each OS are on this page.

Is CVE-2021-38320 being exploited?

CVE-2021-38320 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2021-38320 affect?

CVE-2021-38320 affects simplesamlphp authentication. Severity is medium (CVSS 6.1). The simpleSAMLphp Authentication WordPress plugin is vulnerable to Reflected Cross-Site Scripting due to a reflected $_SERVER["PHP_SELF"] value in the ~/simplesamlphp-authentication.php file which allows attackers to inject arbitrary web sc

How urgent is CVE-2021-38320?

Priority 42/100. Public exploit reference

Software pages

WordPress vulnerabilities · PHP vulnerabilities

References

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