CVE-2021-20867

Advanced Custom Fields versions prior to 5.11 and Advanced Custom Fields Pro versions prior to 5.11 contain a missing authorization vulnerability in moving the field group which may allow a user to move the unauthorized field group via unspecified vectors.

Published: 2021-12-13 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2021-20867 is rated Moderate Risk (51.6/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.75%). Mandatory action: Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-20867

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-03-04 0.58% 0.75% +0.17%
2 2026-03-01 0.75% 0.58% -0.17%
3 2026-02-04 0.75%

Full EPSS history (17 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-20867

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
2.8 3.6 [email protected]
4.0 2.0 MEDIUM
AV:N/AC:L/Au:S/C:N/I:P/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:S)
A single authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
8.0 2.9 [email protected]

Weakness enumeration for CVE-2021-20867

Affected software / configurations for CVE-2021-20867

Vendor Product Version Raw CPE
advancedcustomfields advanced_custom_fields < 5.11 cpe:2.3:a:advancedcustomfields:advanced_custom_fields:*:*:*:*:*:wordpress:*:*
advancedcustomfields advanced_custom_fields < 5.11 cpe:2.3:a:advancedcustomfields:advanced_custom_fields:*:*:*:*:pro:wordpress:*:*

References for CVE-2021-20867

cvelogic Threat Intelligence