Security readout for executives and security teams
Plain-English summary
This flaw lets an unauthenticated person log in as any WordPress user, including an administrator, if they know a valid username. For an affected site, that can mean full site takeover without a password.
Executive priority
Treat this as urgent for any internet-facing WordPress site using RegistrationMagic. The business risk is account takeover and possible full site compromise without stolen credentials.
Technical view
RegistrationMagic versions 5.0.1.7 and earlier lacked identity validation in social_login_using_email(). The CVE describes an authentication bypass, CWE-287, with CVSS 9.8 because it is network-accessible, low-complexity, unauthenticated, and can compromise confidentiality, integrity, and availability.
Likely exposure
Exposure is limited to WordPress sites running RegistrationMagic versions equal to or below 5.0.1.7. Sites with known or easily discoverable usernames, especially administrator usernames, are higher concern.
Exploitation context
The provided sources support unauthenticated remote attack conditions and administrator impersonation if a valid username is known. The bundle does not show CISA KEV listing or cited evidence of active exploitation.
Researcher notes
Focus validation on plugin version, presence of RegistrationMagic, and evidence around the social login path. Do not assume active exploitation from this bundle; KEV is false and no cited source confirms exploitation in the wild.
Mitigation direction
- Upgrade RegistrationMagic to a version newer than 5.0.1.7 per vendor guidance.
- If upgrade cannot be confirmed, disable or remove the plugin until remediated.
- Review WordPress administrator accounts for unauthorized access or changes.
- Check vendor and Wordfence guidance for any additional remediation details.
Validation and detection
- Inventory WordPress sites for the RegistrationMagic plugin.
- Confirm installed RegistrationMagic versions are newer than 5.0.1.7.
- Review authentication logs for suspicious administrator sessions.
- Verify no unauthorized admin users, plugins, themes, or content changes exist.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-287: Credential and account abuse lookup
Authentication and credential weaknesses can make valid-account abuse and credential telemetry useful review starting points. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCredential and access behavior lookup
The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-4073 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H3.95.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://www.wordfence.com/vulnerability-advisories/#CVE-2021-4073CVE reference · x_refsource_MISC
- https://plugins.trac.wordpress.org/changeset/2635173/custom-registration-form-builder-with-submission-manager/trunk/services/class_rm_user_services.phpCVE reference · x_refsource_MISC
- https://www.wordfence.com/blog/2021/12/authentication-bypass-vulnerability-patched-in-user-registration-plugin/CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Authentication
Improper Authentication represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.