Security readout for executives and security teams
Plain-English summary
External Media for WordPress allowed any logged-in user to upload arbitrary files before version 1.0.34. On affected sites, even a low-privilege account could potentially place unsafe content on the server. The supplied sources do not provide a CVSS score or confirm active exploitation.
Executive priority
Prioritize remediation on any public WordPress site using External Media. The business risk is site compromise from a logged-in account, with incomplete public scoring but clear arbitrary upload impact.
Technical view
CVE-2021-24311 is a CWE-434 arbitrary file upload issue in the plugin's wp_ajax_upload-remote-file AJAX action. The affected scope is External Media WordPress plugin versions before 1.0.34. Authentication is required, but the source states any authenticated user could access the vulnerable behavior.
Likely exposure
Exposure is limited to WordPress sites running the External Media plugin before 1.0.34 with user login enabled. Risk increases where untrusted users can create accounts or hold low-privilege roles.
Exploitation context
The bundle does not cite CISA KEV listing or confirmed exploitation. The issue is still serious because authenticated file upload flaws can support deeper compromise depending on upload handling and server configuration.
Researcher notes
The source bundle provides the vulnerable action name and fixed version threshold, but no CVSS vector, proof of exploitation, or detailed patch diff. Avoid assuming unauthenticated reachability or active exploitation without additional evidence.
Mitigation direction
- Update External Media to version 1.0.34 or later.
- Remove the plugin if it is not required.
- Review vendor and plugin advisories for current guidance.
- Audit WordPress users, especially low-privilege or untrusted accounts.
- Inspect recent uploaded media for unexpected file types.
Validation and detection
- Inventory WordPress sites using the External Media plugin.
- Confirm installed plugin version is 1.0.34 or later.
- Check whether public registration or low-trust accounts exist.
- Review upload directories for suspicious recent files.
- Verify no exposed backup or staging site runs an older plugin.
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-434: File access and web shell behavior lookup
File traversal and upload weaknesses can lead teams to review file, web shell, execution, and collection telemetry. 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 lookupFile access behavior lookup
The CVE wording references file access or upload behavior, so file telemetry and web shell review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-24311 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
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
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 and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://wpscan.com/vulnerability/4fb90999-6f91-4200-a0cc-bfe9b34a5de9CVE reference · x_refsource_CONFIRM
- https://www.wordfence.com/blog/2021/05/critical-vulnerability-patched-in-external-media-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.
Unrestricted Upload of File with Dangerous Type
Unrestricted Upload of File with Dangerous Type represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.