How severe is CVE-2021-24307?

CVE-2021-24307 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-24307 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 53% (99th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-24307?

CVE-2021-24307 affects Aioseo All In One Seo. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-24307?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-24307 published?

CVE-2021-24307 was published on 2021-05-24 and last updated on 2026-06-17.

CVE-2021-24307

CVE-2021-24307 is a high-severity vulnerability in Aioseo All In One Seo with a CVSS 3.x base score of 8.8. Its EPSS exploit-prediction score of 53% places it in the 99th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-502.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 9.0
EPSS exploit prediction: 53% (99th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-502
Affected product: Aioseo All In One Seo
Published: 2021-05-24
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2021-24307?: 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.
How severe is CVE-2021-24307?: CVE-2021-24307 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-24307 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 53% (99th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-24307?: CVE-2021-24307 affects Aioseo All In One Seo. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-24307?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-24307 published?: CVE-2021-24307 was published on 2021-05-24 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:aioseo:all_in_one_seo:*:*:*:*:*:wordpress:*:*

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