CVE-2013-5211

MEDIUMCVSS v2 · 5.05.0—
EchelonGraph scoreLOW confidence

This CVE was only ever scored under CVSS v2.0. NVD CVSS v2.0 base 5.0 — v2 rates that MEDIUM (v2 bands: LOW 0.0–3.9 / MEDIUM 4.0–6.9 / HIGH 7.0–10.0; v2 has no CRITICAL band). Vector AV:N/AC:L/Au:N/C:N/I:N/A:P. CVSS v2 is an older, coarser metric than v3.1/v4.0 (no Scope, no User Interaction, no Attack Requirements), so it is not directly comparable to a v3 or v4 score. NVD has never re-scored this record under v3. EPSS predicts 97.8% exploitation probability in the next 30 days, which is reflected in EG Risk but does not lift the v2 base. Confidence: LOW.

Sources: epss, nvd_v2
Weaponized
5.0EG
EchelonGraph verdictPatch this weekExploitation is likely or a public exploit exists.
  • High exploitation likelihood — EPSS 98%
  • Public exploit code is available (Metasploit, epss top5pct, epss high, public exploit)
CISA-KEV: Not listedEPSS PROB: 98%CVSS v2: 5.0Exploit: Metasploit · epss top5pct · epss high · public exploitExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v2.0 (legacy)
5.0MEDIUMNVD never assigned a CVSS v3 rating to this CVE
EG Score
5.0(low)
EG Risk
66(Track)
EG Risk 66/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity50% × 45%
Exploitation98% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
98%
EPSS %ILE
100%
KEV
Not listed

Published

January 2, 2014

Last Modified

April 29, 2026

References (42)

Affected Packages

(1 across 1 ecosystem)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
ntp—1:4.2.8p3+dfsg-1—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 1× in last 7d / 4× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-08-20 22:50 UTCEPSS rescore
  2. 2026-08-08 08:19 UTCOSV refresh
  3. 2026-07-30 16:23 UTCEPSS rescore
  4. 2026-07-26 13:48 UTCEG score recompute▲ 5.00
  5. 2026-07-23 01:16 UTCGHSA enrichment
  6. 2026-07-23 01:14 UTCGHSA enrichment
  7. 2026-07-23 01:12 UTCGHSA enrichment
  8. 2026-07-23 01:10 UTCEG score recompute▼ 9.00
  9. 2026-07-23 00:14 UTCEG score recompute
  10. 2026-07-22 21:52 UTCEG score recompute
  11. 2026-07-22 14:04 UTCEPSS rescore
  12. 2026-07-22 08:37 UTCOSV refresh
  13. 2026-07-15 01:56 UTCEPSS rescore
  14. 2026-07-05 03:51 UTCOSV refresh
  15. 2026-06-28 04:53 UTCEPSS rescore
  16. 2026-06-28 04:53 UTCEPSS rescore
  17. 2026-06-23 21:30 UTCEPSS rescore
  18. 2026-06-23 21:30 UTCEPSS rescore
  19. 2026-06-16 17:49 UTCEPSS rescore
  20. 2026-06-16 17:49 UTCEPSS rescore
  21. 2026-06-16 17:49 UTCEPSS rescore
  22. 2026-06-16 15:14 UTCOSV refresh
  23. 2026-06-15 17:44 UTCEPSS rescore
  24. 2026-06-12 23:08 UTCEPSS rescore
  25. 2026-06-10 22:15 UTCEPSS rescore
Show 23 more
  1. 2026-06-10 13:18 UTCEPSS rescore
  2. 2026-06-04 13:09 UTCEPSS rescore
  3. 2026-06-04 13:09 UTCEPSS rescore
  4. 2026-06-01 13:49 UTCEPSS rescore
  5. 2026-06-01 13:49 UTCEPSS rescore
  6. 2026-05-31 22:28 UTCEPSS rescore
  7. 2026-05-31 22:28 UTCEPSS rescore
  8. 2026-05-29 13:41 UTCEPSS rescore
  9. 2026-05-29 13:41 UTCEPSS rescore
  10. 2026-05-28 21:02 UTCEG score recompute
  11. 2026-05-28 21:02 UTCGHSA enrichment
  12. 2026-05-28 13:42 UTCEPSS rescore
  13. 2026-05-28 13:42 UTCEPSS rescore
  14. 2026-05-28 13:42 UTCEPSS rescore
  15. 2026-05-26 13:41 UTCEPSS rescore
  16. 2026-05-26 13:41 UTCEPSS rescore
  17. 2026-05-22 21:15 UTCEPSS rescore
  18. 2026-05-22 21:15 UTCEPSS rescore
  19. 2026-05-22 21:15 UTCEPSS rescore
  20. 2026-05-22 09:26 UTCOSV refresh
  21. 2026-05-21 22:39 UTCEPSS rescore
  22. 2026-05-18 21:29 UTCEPSS rescore
  23. 2026-05-18 21:29 UTCEPSS rescore

Publicly available exploits

(10 references)

Working exploit code is in the public domain (5 Metasploit modules) (4 GitHub PoCs) (1 Exploit-DB entry). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoC0xhav0c/CVE-2013-5211
    First seen May 3, 2023
    Open source ↗
  • GitHub PoCsepehrdaddev/ntpdos
    First seen Sep 24, 2019

    PoC for distributed NTP reflection DoS (CVE-2013-5211)

    Open source ↗
  • GitHub PoCsuedadam/ntpscanner
    First seen Dec 14, 2014

    NTP monlist scanner CVE-2013-5211

    Open source ↗
  • GitHub PoCdani87/ntpscanner
    First seen Sep 7, 2014

    Scans NTP servers for CVE-2013-5211 NTP DDOS amplification vulnerability.

    Open source ↗
  • Metasploitauxiliary/scanner/ntp/ntp_unsettrap_dos✓ verified
    First seen Aug 25, 2014

    NTP Mode 6 UNSETTRAP DRDoS Scanner

    Open source ↗
  • Metasploitauxiliary/scanner/ntp/ntp_peer_list_dos✓ verified
    First seen Aug 25, 2014

    NTP Mode 7 PEER_LIST DoS Scanner

    Open source ↗
  • Metasploitauxiliary/scanner/ntp/ntp_reslist_dos✓ verified
    First seen Aug 25, 2014

    NTP Mode 7 GET_RESTRICT DRDoS Scanner

    Open source ↗
  • Metasploitauxiliary/scanner/ntp/ntp_req_nonce_dos✓ verified
    First seen Aug 25, 2014

    NTP Mode 6 REQ_NONCE DRDoS Scanner

    Open source ↗
  • Metasploitauxiliary/scanner/ntp/ntp_peer_list_sum_dos✓ verified
    First seen Aug 25, 2014

    NTP Mode 7 PEER_LIST_SUM DoS Scanner

    Open source ↗
  • Exploit-DBEDB-33073
    First seen Apr 28, 2014

    NTP ntpd monlist Query Reflection - Denial of Service

    Open source ↗

Frequently asked(4)

What is CVE-2013-5211?
CVE-2013-5211 is a medium vulnerability published on January 2, 2014. The monlist feature in ntprequest.c in ntpd in NTP before 4.2.7p26 allows remote attackers to cause a denial of service (traffic amplification) via forged (1) REQMONGETLIST or (2) REQMONGETLIST1 requests, as exploited in the wild in December 2013.
When was CVE-2013-5211 disclosed?
CVE-2013-5211 was first published in the National Vulnerability Database on January 2, 2014, with the most recent update on April 29, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2013-5211 actively exploited?
CVE-2013-5211 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 98% probability of exploitation in the next 30 days, which ranks it in the top 0.1% of all scored CVEs.
How do I remediate CVE-2013-5211?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2013-5211, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2013-5211

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