CVE-2021-24356: In the Simple 301 Redirects by BetterLinks WordPress plugin before 2.0.4, a lack of capability checks and insu

This month

HIGH 8.8UPGRADE

CVE-2021-24356 is a high-severity flaw (CVSS 8.8) affecting simple 301 redirects. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In the Simple 301 Redirects by BetterLinks WordPress plugin before 2.0.4, a lack of capability checks and insufficient nonce check on the AJAX action, simple301redirects/admin/activate_plugin, made it possible for authenticated users to activate arbitrary plugins installed on vulnerable sites.

Why this priority

High severity
Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	8.8 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	2.6% (top 15%)
CISA exploited list	No
Weakness	CWE-862
Published	2021-06-14
Last modified	2026-06-17

Publisher (CNA): WPScan · Vendor: wpdeveloper

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

Am I affected?

Timeline

2021-06-14 14:15 UTCPublished CVE record published
2026-06-17 03:39 UTCUpdated Record last modified

wpdeveloper simple 301 redirects UPGRADE

Affected: >= 2.0.0 and < 2.0.4

Fixed in: 2.0.4

Safe to downgrade to: a release before 2.0.0

1. Check installed version

apt-cache policy simple-301-redirects || rpm -q simple-301-redirects || simple-301-redirects --version

2. UPGRADE to 2.0.4 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade simple-301-redirects

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade simple-301-redirects

Note

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

3. If no update is available yet, DOWNGRADE to a release before 2.0.0 (Debian / Ubuntu)

apt-cache madison simple-301-redirects sudo apt install simple-301-redirects=<VERSION_BEFORE_2.0.0> sudo apt-mark hold simple-301-redirects

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list simple-301-redirects sudo dnf downgrade simple-301-redirects-<VERSION_BEFORE_2.0.0> sudo dnf versionlock add simple-301-redirects

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

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-2021-24356?

simple 301 redirects: upgrade to 2.0.4. Exact commands for each OS are on this page.

Is CVE-2021-24356 being exploited?

CVE-2021-24356 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-2021-24356 affect?

CVE-2021-24356 affects simple 301 redirects. Severity is high (CVSS 8.8). In the Simple 301 Redirects by BetterLinks WordPress plugin before 2.0.4, a lack of capability checks and insufficient nonce check on the AJAX action, simple301redirects/admin/activate_plugin, made it possible for authenticated users to act

How urgent is CVE-2021-24356?

Priority 57/100. High severity; Public exploit reference

Software pages

WordPress vulnerabilities

Related CVEs

CVE-2021-24355 MEDIUM 4.3 UPGRADE In the Simple 301 Redirects by BetterLinks WordPress plugin before 2.0.4, the lack of capability checks and in
CVE-2021-24354 HIGH 8.8 UPGRADE A lack of capability checks and insufficient nonce check on the AJAX action in the Simple 301 Redirects by Bet
CVE-2021-24353 HIGH 8.8 UPGRADE The import_data function of the Simple 301 Redirects by BetterLinks WordPress plugin before 2.0.4 had no capab
CVE-2021-24352 HIGH 8.8 UPGRADE The export_data function of the Simple 301 Redirects by BetterLinks WordPress plugin before 2.0.4 had no capab
CVE-2019-15818 MEDIUM 6.1 UPGRADE The simple-301-redirects-addon-bulk-uploader plugin through 1.2.4 for WordPress has no requirement for authent

References

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