NVD / CVE Program· CNA WPScan

CVE-2021-24307: All in One SEO Pack < 4.1.0.2 - Admin RCE via unserialize

Noroxi assessment

Priority: Plan (action score 51/100)

Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
Probability of exploitation in the next 30 days: 53.2% (FIRST EPSS); higher than 98.9% of all records.
Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
According to the record, no fixed version is available yet.

Add it to your regular patch cycle. Update when a fix is released; follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

The All in One SEO – Best WordPress SEO Plugin – Easily Improve Your SEO Rankings before 4.1.0.2 enables authenticated users with "aioseo_tools_settings" privilege (most of the time admin) to execute arbitrary code on the underlying host. Users can restore plugin's configuration by uploading a backup .ini file in the section "Tool > Import/Export". However, the plugin attempts to unserialize values of the .ini file. Moreover, the plugin embeds Monolog library which can be used to craft a gadget chain and thus trigger system command execution.

HighCVSS 8.8 · v3.1—Proof of concept No fix recorded

Published: May 24, 2021
Updated: Jun 16, 2026
EPSS: 53.2% · 98th percentile
CWE: CWE-502

Report tools

JSON

Action score

Plan

Add it to your regular patch cycle.

CVSS: 35 / 40 · 8.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 16 / 30 · 53.2%

Is All in One SEO – AI SEO Plugin to Boost SEO Rankings & Traffic (Schema, Local SEO, Sitemap & SEO Insights) on your site?

WP Lens reads your site's plugin, theme and WordPress versions from the outside and matches them to known vulnerabilities. Works without an account.

If any of these changes, we'll tell you in the daily email digest.

Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
aioseo	all in one seo	cpe:2.3:a:aioseo:all_in_one_seo

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

aioseo all in one seobefore 4.1.0.2

Versions reported by the vendor

Affected version ranges reported by the assigning authority (WPScan). Independent of NVD's CPE analysis and usually ahead of it.

All in One SEO Team All in One SEO – Best WordPress SEO Plugin – Easily Improve Your SEO Rankings
- 4.1.0.2 and later · before 4.1.0.2affected

Same product

aioseo: all records

Other highest-scoring records for the same primary product.

CVE-2021-25036All In One SEO < 4.1.5.3 - Authenticated Privilege Escalation
36Monitor
CVE-2022-38093WordPress All in One SEO plugin <= 4.2.3.1 - Multiple Cross-Site Request Forgery (CSRF) vulnerabilities
35Monitor
CVE-2022-42494WordPress All in One SEO Pro plugin <= 4.2.5.1 - Server Side Request Forgery (SSRF) vulnerability
26Monitor

Published before and after this one in the same product

Later →CVE-2021-25037Jan 17, 2022 · All In One SEO < 4.1.5.3 - Authenticated SQL Injection
26Monitor
Later →CVE-2023-0585Feb 24, 2023 · All in One SEO Pack <= 4.2.9 - Authenticated (Administrator+) Stored Cross-Site Scripting
19Monitor
Later →CVE-2023-0586Feb 24, 2023 · All in One SEO Pack <= 4.2.9 - Authenticated (Contributor+) Stored Cross-Site Scripting
22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

Proof-of-concept repository on GitHub ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
Source	Kind	Date
Proof-of-concept repository on GitHub	stars:4	2022-01-02

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

PublishedMay 24, 2021
First PoCJan 2, 2022+223 d
TodayNov 8, 2026+1994 d

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Vincent MICHEL

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
A low-privileged account is enough.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: high · data can be read
Integrity: high · data or configuration can be modified
Availability: high · the service can be disrupted

Attack vector: Network
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-502 · Deserialization of Untrusted Data

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

nvd-primary

Root cause

Data received over the network is deserialized into the language’s native object format without verifying its source. Code paths inside the object can be triggered during deserialization.

The bug in code

The whole CWE-502 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

python

1payload = sock.recv(65536)
2job = pickle.loads(payload)

Fixed

python

1payload = sock.recv(65536)
2if not hmac.compare_digest(sign(payload), header_sig):
3    raise PermissionError("invalid signature")
4job = JobSchema.validate(json.loads(payload))

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

Object InjectionCAPEC-586likelihood: Medium · High

ATT&CK techniques

—

Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

aioseo.com/changelog/

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records