Security readout for executives and security teams
Plain-English summary
This is a reflected cross-site scripting issue in a WordPress Custom Menu Plugin parameter. An attacker could trick a user into opening a crafted page or link that runs unwanted script in the victim’s browser. The issue is medium severity because user interaction is required and the expected impact is limited confidentiality and integrity exposure.
Executive priority
Treat this as a moderate web application risk. Prioritize internet-facing WordPress sites, especially where administrator sessions or authenticated users may be targeted through phishing or malicious links.
Technical view
CVE-2021-38321 affects Custom Menu Plugin versions up to and including 1.3.3. The selected_menu parameter in custom-menus.php is reported as improperly handling input, enabling reflected XSS. CVSS 3.1 is 6.1 with network attack vector, low complexity, no privileges required, user interaction required, changed scope, and low confidentiality/integrity impact.
Likely exposure
Exposure is most likely on WordPress sites running Custom Menu Plugin version 1.3.3 or earlier. The provided sources do not identify other affected products or platforms.
Exploitation context
The source bundle does not show CISA KEV listing or active exploitation evidence. Exploitation would require user interaction, consistent with reflected XSS, such as a victim visiting attacker-controlled or attacker-influenced content.
Researcher notes
Evidence is limited to the CVE description, Wordfence advisory reference, and WordPress plugin source reference. No exploit status, fixed version, or official mitigation details are provided in the bundle.
Mitigation direction
- Inventory WordPress sites for Custom Menu Plugin version 1.3.3 or earlier.
- Check the vendor plugin repository and Wordfence advisory for fixed-version guidance.
- Disable or remove the plugin if it is not required.
- Use WAF or WordPress security controls to reduce reflected XSS risk.
Validation and detection
- Confirm whether the plugin is installed on each WordPress site.
- Record the installed plugin version and compare it to 1.3.3 or earlier.
- Review web logs for unusual requests referencing selected_menu.
- Verify remediation against vendor or advisory guidance before closing.
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-79: 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-2021-38321 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
- Medium
- CVSS
- 6.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
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:C/C:L/I:L/A:N2.82.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.1MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://www.wordfence.com/vulnerability-advisories/#CVE-2021-38321CVE reference · x_refsource_MISC
- https://plugins.trac.wordpress.org/browser/custom-sub-menus/trunk/custom-menus.php?rev=2205549#L136CVE 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.