CVE-2022-4120: The Stop Spammers Security | Block Spam Users, Comments, Forms WordPress plugin before 2022.6 passes base64 en

Q: How do I fix CVE-2022-4120?

stop spammers: upgrade to 2022.6. Exact commands for each OS are on this page.

Q: Is CVE-2022-4120 being exploited?

CVE-2022-4120 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-2022-4120 affect?

CVE-2022-4120 affects stop spammers. Severity is critical (CVSS 9.8). The Stop Spammers Security | Block Spam Users, Comments, Forms WordPress plugin before 2022.6 passes base64 encoded user input to the unserialize() PHP function when CAPTCHA are used as second challenge, which could lead to PHP Object injec

Q: How urgent is CVE-2022-4120?

Priority 72/100. Critical severity; EPSS top 3%: very likely to be exploited; Public exploit reference; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

This week

CRITICAL 9.8REMOTEUPGRADE

CVE-2022-4120 is a critical-severity flaw (CVSS 9.8) affecting stop spammers. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The Stop Spammers Security | Block Spam Users, Comments, Forms WordPress plugin before 2022.6 passes base64 encoded user input to the unserialize() PHP function when CAPTCHA are used as second challenge, which could lead to PHP Object injection if a plugin installed on the blog has a suitable gadget chain

Why this priority

Critical severity
EPSS top 3%: very likely to be exploited
Public exploit reference
CISA SSVC: automatable with total technical impact
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	18.1% (top 3%)
CISA exploited list	No
Published	2022-12-26
Last modified	2026-06-17

Publisher (CNA): WPScan · Vendor: trumani

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

Am I affected?

Timeline

2022-12-26 13:15 UTCPublished CVE record published
2026-06-17 05:20 UTCUpdated Record last modified

trumani stop spammers UPGRADE

Affected: < 2022.6

Fixed in: 2022.6

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy stop-spammers || rpm -q stop-spammers || stop-spammers --version

2. UPGRADE to 2022.6 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade stop-spammers

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade stop-spammers

Note

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

Exact fixes by distribution

Fedora ELN · libslirp · FIXED · 4.9.7-1.eln159 · FEDORA-2026-209cb94e13 · source

sudo dnf upgrade --advisory=FEDORA-2026-209cb94e13

Fedora 46 · modpoll · FIXED · 1.6.1-1.fc46 · FEDORA-2026-60d403ff15 · source

sudo dnf upgrade --advisory=FEDORA-2026-60d403ff15

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Write-up: wpscan.com/vulnerability/e8bb79db-ef77-43be-b449-4c4b5310eedf

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-2022-4120?

stop spammers: upgrade to 2022.6. Exact commands for each OS are on this page.

Is CVE-2022-4120 being exploited?

CVE-2022-4120 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-2022-4120 affect?

CVE-2022-4120 affects stop spammers. Severity is critical (CVSS 9.8). The Stop Spammers Security | Block Spam Users, Comments, Forms WordPress plugin before 2022.6 passes base64 encoded user input to the unserialize() PHP function when CAPTCHA are used as second challenge, which could lead to PHP Object injec

How urgent is CVE-2022-4120?

Priority 72/100. Critical severity; EPSS top 3%: very likely to be exploited; Public exploit reference; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

Software pages

WordPress vulnerabilities · PHP vulnerabilities

Related CVEs

CVE-2023-2489 MEDIUM 4.8 UPGRADE The Stop Spammers Security | Block Spam Users, Comments, Forms WordPress plugin before 2023 does not sanitise
CVE-2023-2488 MEDIUM 6.1 UPGRADE The Stop Spammers Security | Block Spam Users, Comments, Forms WordPress plugin before 2023 does not sanitise

References

← Back to latest CVEs