Security readout for executives and security teams
Plain-English summary
CVE-2021-39348 is a stored cross-site scripting issue in the LearnPress WordPress LMS plugin. An administrator-level user could save script content through a custom profile parameter when WordPress HTML filtering is disabled. The main concern is abuse inside managed or multisite environments where administrators are not meant to run arbitrary scripts.
Executive priority
Treat this as a moderate-priority hygiene issue. It is not shown as actively exploited and requires admin access, but it undermines delegated trust models and should be remediated during normal WordPress plugin patch cycles.
Technical view
LearnPress versions up to and including 4.1.3.1 insufficiently escaped the $custom_profile parameter in inc/admin/views/backend-user-profile.php. The CVSS 3.1 score is 5.5 with high privileges required, no user interaction, changed scope, and low confidentiality and integrity impact. The weakness is mapped to CWE-80.
Likely exposure
Exposure is limited to WordPress sites running LearnPress 4.1.3.1 or earlier, especially multisite installations where unfiltered_html is disabled for administrators, or sites where unfiltered_html is disabled generally.
Exploitation context
The source bundle does not show CISA KEV listing or other evidence of active exploitation. The issue requires authenticated administrative access, reducing broad internet-scale risk, but it can matter in delegated-admin, agency, education, or multisite environments.
Researcher notes
This is separate from CVE-2021-24702. The key technical condition is insufficient output escaping of $custom_profile in the backend user profile view. Evidence in the bundle does not identify a fixed version number, so confirm remediation from vendor or advisory sources.
Mitigation direction
- Upgrade LearnPress beyond affected versions after confirming vendor guidance and release notes.
- Review WordPress multisite deployments where administrator HTML filtering is intentionally restricted.
- Limit administrator access to trusted users and remove stale privileged accounts.
- Check vendor and Wordfence advisories for confirmed remediation details.
- Monitor admin profile changes for unexpected script content.
Validation and detection
- Inventory WordPress sites for LearnPress versions 4.1.3.1 and earlier.
- Confirm whether affected sites use multisite or disabled unfiltered_html behavior.
- Review LearnPress profile customization paths for stored script content.
- Verify patched LearnPress files align with the referenced WordPress Trac changeset.
- Document administrator accounts with permission to modify LearnPress profile settings.
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-80: 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-2021-39348 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
- 5.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/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:H/UI:N/S:C/C:L/I:L/A:N2.32.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.5MediumVector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=2614592%40learnpress&new=2614592%40learnpress&sfp_email=&sfph_mail=CVE reference · x_refsource_MISC
- https://wordfence.com/vulnerability-advisories/#CVE-2021-39348CVE reference · x_refsource_MISC
- https://github.com/BigTiger2020/word-press/blob/main/LearnPress.mdCVE 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 Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)
Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS) represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.