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Fencer Intel
high 8.1

CVE-2021-24217 json

Facebook for WordPress < 3.0.0 - PHP Object Injection with POP Chain

published 5y ago modified 4mo ago also EUVD-2021-11131

cvss
8.1
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
3.5%
EPSS 3.5% chance of exploitation in 30 days, percentile 89%
public exploits
0
none known

Summary

The run_action function of the Facebook for WordPress plugin before 3.0.0 deserializes user supplied data making it possible for PHP objects to be supplied creating an Object Injection vulnerability. There was also a useable magic method in the plugin that could be used to achieve remote code execution.

Patch / fix

  • facebook facebook 3.0.0

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Exploit prediction

3.52% chance of exploitation in the next 30 days, higher than 89% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • wpscan.com https://wpscan.com/vulnerability/509f2754-a1a1-4142-9126-ae023a88533a referenced PoC, tagged "exploit" by a source, unverified
  • wordfence.com https://www.wordfence.com/blog/2021/03/two-vulnerabilities-patched-in-facebook-for-wordpress-plugin/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 6.8 AV:N/AC:M/Au:N/C:P/I:P/A:P

Affected products

  • Unknown Facebook for WordPress

Classification

Weakness
  • CWE-502 Deserialization of Untrusted Data
Technology feeds

References

Sources

Fencer Intel 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.