Vulnerability report

High confidence Not in CISA KEV

CVE-2013-5211

NTP Denial of Service

NTP

Watch CVE-2013-5211 Browse KEV feed
Severity
CVSS 5.0 · Medium
Confidence
High
Exploit status
—
EPSS
97.5%
First observed
—
Last observed
—

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2013-5211 is an unauthenticated vulnerability affecting NTP. The monlist feature in ntp_request.c in ntpd in NTP before 4.2.7p26 allows remote attackers to cause a denial of service (traffic amplification) via...

Is it exploited?

Yes. Previdian tracks this CVE as a known exploited vulnerability. Confidence is high. Also confirmed by third-party sources.

Who is affected?

NTP.

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

NTP Denial of Service

The monlist feature in ntp_request.c in ntpd in NTP before 4.2.7p26 allows remote attackers to cause a denial of service (traffic amplification) via forged (1) REQ_MON_GETLIST or (2) REQ_MON_GETLIST_1 requests, as exploited in the wild in December 2013.

View vendor advisory (opens in new tab)
Published
02 Jan 2014
Exploitation Reported
02 Jan 2014
Attack vector
Remote
Complexity
Low
Privileges
None
User interaction
—

CVE References

Exploitation evidence

Why Previdian marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

No exploitation evidence rows are recorded for this CVE yet.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the Previdian Pro API.

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Source Added
CVE First 2014-01-02 11:00 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets
User-Agents
Callback hosts
0
0
0

Request targets and User-Agents available in Pro. Callback host details available in Enterprise.

Scanner coverage

No scanner integrations recorded yet.

Virtual patch status

No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

No detection artifacts or sensor request patterns are available for this CVE yet.

Check back as sensor telemetry and scanner integrations are updated.

Risk and context

Severity, weaknesses, and research context

CVSS v2.0

5.0 Medium

Potential damage if exploited. Separate from whether attackers are using it.

AV:N/AC:L/Au:N/C:N/I:N/A:P

EPSS

97.5%

Estimated chance of exploitation in the next 30 days. Previdian's warning comes from evidence, not this score.

Weaknesses

Improper Input Validation CWE-20

Timeline

From disclosure to observed exploitation

  1. 11:00 UTC

    Added to Previdian KEV Feed

    High-confidence, third-party attested exploitation

  2. 11:00 UTC

    CVE published

    Vulnerability disclosed publicly

  3. 00:00 UTC

    CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2013-5211

Free JSON includes basic KEV fields 
{
  "cve_id": "CVE-2013-5211",
  "confidence": "High",
  "cvss_score": 5.0,
  "cvss_estimated": false,
  "epss_score": 0.97549,
  "exploit_status": {
    "exploited_in_the_wild": false,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}