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Fencer Vulns
high 8.8

CVE-2021-24307 in the critical feed json

All in One SEO Pack < 4.1.0.2 - Admin RCE via unserialize

published 2021-05-24 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-11221

cvss
8.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
53.3%
EPSS 53.3% chance of exploitation in 30 days, percentile 98%
public exploits
0
none known

Summary

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.

Patch / fix

  • aioseo all_in_one_seo 4.1.0.2

Exploit prediction

53.27% chance of exploitation in the next 30 days, higher than 98% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • wpscan.com https://wpscan.com/vulnerability/ab2c94d2-f6c4-418b-bd14-711ed164bcf1 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 9.0 AV:N/AC:L/Au:S/C:C/I:C/A:C

Affected products

  • All in One SEO Team All in One SEO – Best WordPress SEO Plugin – Easily Improve Your SEO Rankings

Classification

Weakness
  • CWE-502 Deserialization of Untrusted Data
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.