Security readout for executives and security teams
Plain-English summary
A WordPress plugin used to customize admin login pages allowed a tricked site administrator to save attacker-supplied script into plugin settings. That script could persist and run for users who view the affected page. Public WordPress sites using this plugin should treat it as a high-priority web compromise risk.
Executive priority
Prioritize remediation for internet-facing WordPress sites because stored XSS in an admin-facing plugin can support account compromise, site defacement, or malicious redirects. Urgency is high, but exploitation evidence in the provided sources is incomplete.
Technical view
CVE-2021-34628 is a CSRF flaw in Weblizar Admin Custom Login through 3.2.7, tied to the loginbgSave action in Login-form-background.php. The published impact is stored XSS with CVSS 3.1 score 8.8 and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is limited to WordPress installations running Admin Custom Login version 3.2.7 or earlier. Sites without this plugin, or with a vendor-confirmed fixed version, are not indicated as affected by the supplied sources.
Exploitation context
The CVSS vector indicates network attackability, low complexity, no attacker privileges, and required user interaction. The bundle does not show CISA KEV listing or other cited evidence of active exploitation, so active exploitation should not be claimed.
Researcher notes
The source bundle identifies CWE-352 and references the vulnerable loginbgSave path. It does not provide a confirmed fixed version, patch diff, exploitation-in-the-wild evidence, or detailed affected-version range beyond versions up to and including 3.2.7.
Mitigation direction
- Inventory WordPress sites for Admin Custom Login versions 3.2.7 or earlier.
- Check Weblizar or WordPress plugin guidance for a fixed version.
- Upgrade only to a vendor-confirmed fixed release when available.
- Disable or remove the plugin if a fix cannot be verified.
- Limit WordPress administrator exposure and enforce admin MFA.
Validation and detection
- Confirm plugin name and version from WordPress administration or asset inventory.
- Review affected sites for unexpected custom login-page scripts or plugin settings.
- Check web logs for suspicious administrator setting changes around login customization.
- Verify remediation by confirming the vulnerable plugin version is absent.
- Document any compensating controls if immediate removal is not possible.
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-352: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. 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 lookupCVE-2021-34628 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
- High
- CVSS
- 8.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/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:R/S:U/C:H/I:H/A:H2.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.8HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://www.wordfence.com/vulnerability-advisories/#CVE-2021-34628CVE reference · x_refsource_MISC
- https://plugins.trac.wordpress.org/browser/admin-custom-login/tags/3.2.7/includes/login-form-setting/login-form-background.php#L686CVE 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.
Cross-Site Request Forgery (CSRF)
Cross-Site Request Forgery (CSRF) represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.