Security readout for executives and security teams
Plain-English summary
This is a stored cross-site scripting flaw in the WP Upload Restriction WordPress plugin. A low-privileged authenticated user could save malicious script content that later runs in another user’s browser. The impact is limited but can affect confidentiality and integrity inside the WordPress site.
Executive priority
Treat as a moderate web application risk. It should be remediated in normal vulnerability cycles, faster for sites with many contributors, customer accounts, or shared administrative workflows.
Technical view
CVE-2021-34625 affects WP Upload Restriction versions 2.2.3 and prior. The reported issue is improper script handling in the saveCustomType function, classified as CWE-79. CVSS 3.1 is 6.4 with network access, low complexity, low privileges required, changed scope, and low confidentiality and integrity impact.
Likely exposure
Exposure is likely limited to WordPress sites with WP Upload Restriction 2.2.3 or earlier installed and reachable by low-level authenticated users. Public internet exposure alone is not enough; the attacker needs an account with access to the vulnerable behavior.
Exploitation context
The source bundle does not show CISA KEV listing or cited evidence of active exploitation. The issue is still meaningful because stored XSS can persist and execute when affected WordPress content or administrative views are loaded.
Researcher notes
Evidence is limited to the CVE record and Wordfence advisory reference in the bundle. No exploit code, patch version, or active exploitation claim is provided. Validation should focus on plugin presence, version, reachable authenticated functionality, and whether suspicious stored content exists.
Mitigation direction
- Inventory WordPress sites for WP Upload Restriction installations and versions.
- Check vendor or Wordfence guidance for a fixed version or recommended replacement.
- Upgrade, remove, or disable affected plugin versions according to vendor guidance.
- Limit low-privileged user access to affected plugin functionality until remediated.
- Review WordPress roles and remove unnecessary accounts.
Validation and detection
- Confirm whether WP Upload Restriction is installed on each WordPress site.
- Verify installed plugin versions are newer than 2.2.3 or otherwise remediated.
- Review plugin configuration for unexpected script-like saved values.
- Check recent WordPress user activity for changes by low-privileged accounts.
- Confirm no affected public or administrative route remains reachable to untrusted users.
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-2021-34625 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
- 6.4 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/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:L/UI:N/S:C/C:L/I:L/A:N3.12.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.4MediumVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://www.wordfence.com/vulnerability-advisories/#CVE-2021-34625CVE 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 Input During Web Page Generation ('Cross-site Scripting')
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.