CVE-2021-4458
High PUBLISHEDModern Events Calendar Lite <= 6.3.0 - Unauthenticated SQL Injection
Not yet in CISA KEV
Recommended Action
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
At a Glance
The Modern Events Calendar Lite plugin for WordPress is vulnerable to SQL Injection via the 'id' parameter of the 'wp_ajax_mec_load_single_page' AJAX action in all versions up to, and including, 6.3.0 due to insufficient escaping on the user supplied parameter and lack of sufficient preparation on the existing SQL query. This makes it possible for unauthenticated attackers to append additional SQL queries into already existing queries that can be used to extract sensitive information from the database. This is only exploitable on sites with addslashes disabled.
- CVE Published
- Jul 12, 2025
- Exploitation Reported
- Jun 06, 2026
- CVSS
- 5.9 Medium
- EPSS
- 0.4%
Affected Versions
| Vendor | Product | Version | Status |
|---|---|---|---|
| webnus/ |
Modern Events Calendar Lite
|
* to <= 6.3.0 |
Affected |
CVE References
- wordfence.com/threat-intel/vulnerabilities/id/703ba736-583... wordfence.com · CVE Record https://www.wordfence.com/threat-intel/vulnerabilities/id/703ba736-58...
- plugins.trac.wordpress.org/changeset/2683727/modern-events-calendar-lit... plugins.trac.wordpress.org · CVE Record https://plugins.trac.wordpress.org/changeset/2683727/modern-events-ca...
Recommended Actions
- Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
- Use the Pro API to automate enrichment, telemetry, and workflow delivery for VM, SOC, and CTI pipelines.
Known Exploited Vulnerability Sources
Catalogues that list this CVE as a known exploited vulnerability.
Per-source evidence links for KEV attestations are available through the KEVIntel Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| The Shadowserver First | 2026-06-06 00:00 UTC |
No detection artifacts or sensor request patterns are available for this CVE yet.
Check back as sensor telemetry and scanner integrations are updated.
Virtual Patch
Compensating WAF rules to help reduce exposure to this CVE. Rule content and deployable vendor exports are available with KEVIntel Enterprise.
KEVIntel does not currently have a virtual patch for this CVE. When available, KEVIntel virtual patches ship as deployable ModSecurity, Cloudflare, and AWS WAF rules.
Enterprise feature. Virtual patch rule content and deployable vendor exports (ModSecurity, Cloudflare, AWS WAF) are available to KEVIntel Enterprise users.
CVSS Scores
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Exploitation Status
Exploited in the wild
Recorded 2026-06-06 00:00:00 UTC · The Shadowserver
Weaknesses (CWE)
-
Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')
Timeline
Key exploitation, disclosure, scanner coverage, and KEV attestation events for this CVE.
-
00:00 UTC about 1 month ago00:00 UTC · about 1 month ago
Added to KEVIntel KEV Feed
High-confidence, third-party attested exploitation
-
11:23 UTC about 1 year ago11:23 UTC · about 1 year ago
CVE published
Vulnerability disclosed publicly
-
22:07 UTC about 1 year ago22:07 UTC · about 1 year ago
CVE ID reserved
Identifier reserved by the CNA
Automate This Intelligence with the Pro API
Confidence scoring, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
Pro API Example
GET /api/v2/pro/kevs/CVE-2021-4458
{
"cve_id": "CVE-2021-4458",
"title": "Modern Events Calendar Lite <= 6.3.0 - Unauthenticated SQL Injection",
"affected_vendor": "webnus",
"affected_product": "Modern Events Calendar Lite",
"affected_versions": [
{ "vendor": "...", "product": "...", "status": "affected", "display_label": "..." }
],
"confidence": "High",
"cvss_score": 5.9,
"epss_score": 0.00354,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "...": "Pro API fields" },
"proof_of_concepts": [ "..." ],
"scanner_integrations": [ "..." ]
}