Security readout for executives and security teams
Plain-English summary
This issue affects WordPress sites using Modern Events Calendar Lite 6.3.0 or older. An unauthenticated attacker may be able to read sensitive database information through a vulnerable AJAX request, but exploitation depends on addslashes being disabled and is rated high complexity.
Executive priority
Treat this as a targeted data-exposure risk, not an emergency wormable issue. Prioritize internet-facing WordPress sites with the plugin installed, especially where customer or operational data resides in the database.
Technical view
CVE-2021-4458 is CWE-89 SQL injection in the id parameter of the wp_ajax_mec_load_single_page AJAX action. The cited description attributes it to insufficient escaping and query preparation. CVSS 3.1 is 5.9, with high confidentiality impact and no stated integrity or availability impact.
Likely exposure
Exposure is likely limited to WordPress installations running Modern Events Calendar Lite up to and including 6.3.0, where the vulnerable AJAX path is reachable and addslashes is disabled. The bundle does not identify other affected products.
Exploitation context
The source bundle says exploitation is unauthenticated and network reachable, but high complexity. It states the issue can extract sensitive database information. KEV is false, and no cited source in the bundle states active exploitation.
Researcher notes
Evidence supports unauthenticated SQL injection with a narrow environmental prerequisite. The bundle does not provide exploit telemetry, a KEV listing, or a precise fixed version label. Validate against the Wordfence entry and WordPress Trac changeset before closing exposure.
Mitigation direction
- Inventory WordPress sites using Modern Events Calendar Lite.
- Flag plugin installations at version 6.3.0 or older.
- Update the plugin using vendor or WordPress.org guidance.
- Confirm the local code includes the referenced query-hardening changes.
- Review database exposure assumptions if vulnerable versions were publicly reachable.
Validation and detection
- Check installed Modern Events Calendar Lite versions across WordPress sites.
- Verify whether addslashes is disabled in affected environments.
- Review web logs for requests to the vulnerable AJAX action.
- Compare local render.php behavior with the WordPress Trac changeset.
- Confirm remediation in a staging site before production rollout.
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-89: Database access and collection lookup
Injection into data stores can inform collection, data access, and exfiltration detection reviews. 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 lookupDatabase behavior lookup
The CVE wording references database injection or access, so collection and exfiltration review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-4458 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
- 5.9 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/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:H/PR:N/UI:N/S:U/C:H/I:N/A:N2.23.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.9MediumVector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
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 Special Elements used in an SQL Command ('SQL Injection')
Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.