How severe is CVE-2021-24217?

CVE-2021-24217 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-24217 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (88th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-24217?

CVE-2021-24217 affects Facebook. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-24217?

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-2021-24217 published?

CVE-2021-24217 was published on 2021-04-12 and last updated on 2026-06-17.

CVE-2021-24217

CVE-2021-24217 is a high-severity vulnerability in Facebook with a CVSS 3.x base score of 8.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-502.

Key facts

Severity: High (CVSS 3.x base score 8.1)
CVSS v2: 6.8
EPSS exploit prediction: 4% (88th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-502
Affected product: Facebook
Published: 2021-04-12
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2021-24217?: 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.
How severe is CVE-2021-24217?: CVE-2021-24217 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-24217 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (88th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-24217?: CVE-2021-24217 affects Facebook. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-24217?: 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-2021-24217 published?: CVE-2021-24217 was published on 2021-04-12 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:facebook:facebook:*:*:*:*:*:wordpress:*:*

More vulnerabilities in Facebook

CVE-2008-0660 — Critical (CVSS 9.3): Multiple stack-based buffer overflows in Aurigma Image Uploader ActiveX control (ImageUploader4.ocx) 4.6.17.0,…
CVE-2021-24218 — High (CVSS 8.8): The wp_ajax_save_fbe_settings and wp_ajax_delete_fbe_settings AJAX actions of the Facebook for WordPress plugin before…
CVE-2014-6392 — Medium (CVSS 4.3): Cross-site scripting (XSS) vulnerability in the Facebook app 14.0 and the Facebook Messenger app 10.0 for iOS allows…

All CVEs affecting Facebook →

Other CWE-502 (Deserialization of Untrusted Data) vulnerabilities

CVE-2026-41104 — Critical (CVSS 10.0): Deserialization of untrusted data in Microsoft Planetary Computer Pro allows an unauthorized attacker to disclose…
CVE-2026-43633 — Critical (CVSS 10.0): HestiaCP versions 1.9.0 through 1.9.4 contain a deserialization vulnerability in the web terminal component caused by a…
CVE-2026-33819 — Critical (CVSS 10.0): Deserialization of untrusted data in Microsoft Bing allows an unauthorized attacker to execute code over a network.
CVE-2026-20131 — Critical (CVSS 10.0): A vulnerability in the web-based management interface of Cisco Secure Firewall Management Center (FMC) Software could…
CVE-2026-25632 — Critical (CVSS 10.0): EPyT-Flow is a Python package designed for the easy generation of hydraulic and water quality scenario data of water…
CVE-2025-14931 — Critical (CVSS 10.0): Hugging Face smolagents Remote Python Executor Deserialization of Untrusted Data Remote Code Execution Vulnerability.…

Browse all CWE-502 (Deserialization of Untrusted Data) vulnerabilities →