CVE-2018-12327

CRITICALNVD 9.89.8
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to NVD's CVSS score.

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2022-05-13. NVD baseline CVSS 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3
Trending — 4 sources updated this weekElevated

Also known asEUVD-2018-4301 (ENISA EUVD) · GHSA-gmx7-j3pp-2gxp (GitHub Security Advisories)Source: ENISA EUVD

9.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • Public exploit or proof-of-concept code is available
CISA-KEV: Not listedEPSS PROB: 28%CVSS: 9.8Exploit: Public PoCExposed services: Not assessed

A fix is available — apply it.

Stack-based buffer overflow in ntpq and ntpdc of NTP version 4.2.8p11 allows an attacker to achieve code execution or escalate to higher privileges via a long string as the argument for an IPv4 or IPv6 command-line parameter. NOTE: It is unclear whether there are any common situations in which ntpq or ntpdc is used with a command line from an untrusted source.

CVSS v3
9.8
EG Score
9.8CRITICALmedium confidence
EG Risk
60
EG Risk 60/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity98% × 45%
Impact severity (EG Severity): CVSS 9.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability0% × 15%
CISA's BOD 26-04 default: no one has published Automatable for this CVE, and CISA treats it as “no” for a CVE not in KEV.
SSVC (CISA's decision table, applied by EchelonGraph): Track at low, Track* at medium and Attend at high mission impact.
Exploitation public PoC (exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
28%
EPSS %ILE
98th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (9.8): severity, escalated by confirmed exploitation. This CVE's 9.8 is its impact severity (EG Severity), not escalated.

EG Severity
9.8 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
28% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-31). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track* at medium mission impactTrack at low, Track* at medium and Attend at high mission impact.CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low, Track* at medium and Attend at high mission impact.

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

June 20, 2018

Last Modified

November 21, 2024

Advisory Details (8)

Auto-updated Oct 6, 2026
Patch available. Sources: redhat.
Web page

CVE-2018-12327 - PSIRT.COM

http://www.securityfocus.com/bid/104517
Web page

ntp 4.2.8p11 - Local Buffer Overflow (PoC) - Linux dos Exploit

https://www.exploit-db.com/exploits/44909/
Web page

NTP: Multiple vulnerabilities (GLSA 201903-15) — Gentoo security

https://security.gentoo.org/glsa/201903-15
Red HatMentions a patch (unverified)

Affected: Red Hat Enterprise Linux 7.

https://access.redhat.com/errata/RHSA-2019:2077
Red HatMentions a patch (unverified)

Affected: Red Hat Enterprise Linux 6.

https://access.redhat.com/errata/RHSA-2018:3854
Red HatMentions a patch (unverified)

Affected: Red Hat Enterprise Linux 6.7 Extended Update Support.

https://access.redhat.com/errata/RHSA-2018:3853

Patch Availability(6)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntuntpdate (1:4.2.8p10+dfsg-5ubuntu7.3+esm1) @ bionic2026-11-01ubuntu
ubuntuntpdate (1:4.2.8p4+dfsg-3ubuntu5.10) @ xenial2026-11-01ubuntu
redhatntp-0:4.2.6p5-28.el7_6.12020-04-14redhat
redhatntp-0:4.2.6p5-29.el72019-08-06redhat
redhatntp-0:4.2.6p5-15.el6_102018-12-19redhat
redhatntp-0:4.2.6p5-5.el6_7.62018-12-19redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(1 across 1 ecosystem)
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
ntp1:4.2.8p15+dfsg-1 ... 1:4.2.8p15+dfsg-2~hurd.1 (6 versions)
  • every version on: no fix on record
—

Weakness Classification(1)

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

All Vendor Advisories

(6)

Data Freshness Timeline

(refreshed 26× in last 7d / 89× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 99 of 231 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 1 repeat row among the latest 100 is merged into the row it repeats. The 132 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-01 16:28 UTCEPSS rescoreEPSS 28% · 98th percentile
  2. 2026-11-01 10:51 UTCEG score recompute
  3. 2026-11-01 10:51 UTCVendor advisory
  4. 2026-11-01 10:51 UTCGHSA enrichmentGHSA-gmx7-j3pp-2gxp · GitHub severity CRITICAL · GitHub CVSS 9.8
  5. 2026-10-31 16:27 UTCEPSS rescoreEPSS 28% · 98th percentile
  6. 2026-10-31 11:09 UTCEG score recompute
  7. 2026-10-31 11:09 UTCVendor advisory
  8. 2026-10-31 11:08 UTCGHSA enrichmentGHSA-gmx7-j3pp-2gxp · GitHub severity CRITICAL · GitHub CVSS 9.8
  9. 2026-10-30 16:28 UTCEPSS rescoreEPSS 28% · 98th percentile
  10. 2026-10-30 11:25 UTCEG score recompute
  11. 2026-10-30 11:25 UTCVendor advisory
  12. 2026-10-30 11:25 UTCGHSA enrichmentGHSA-gmx7-j3pp-2gxp · GitHub severity CRITICAL · GitHub CVSS 9.8
  13. 2026-10-29 16:28 UTCEPSS rescoreEPSS 28% · 98th percentile
  14. 2026-10-29 11:42 UTCEG score recompute
  15. 2026-10-29 11:42 UTCVendor advisory
  16. 2026-10-29 11:42 UTCGHSA enrichmentGHSA-gmx7-j3pp-2gxp · GitHub severity CRITICAL · GitHub CVSS 9.8
  17. 2026-10-28 16:27 UTCEPSS rescoreEPSS 28% · 98th percentile
  18. 2026-10-28 12:00 UTCEG score recompute
  19. 2026-10-28 12:00 UTCVendor advisory
  20. 2026-10-28 12:00 UTCGHSA enrichmentGHSA-gmx7-j3pp-2gxp · GitHub severity CRITICAL · GitHub CVSS 9.8
  21. 2026-10-27 16:27 UTCEPSS rescoreEPSS 28% · 98th percentile
  22. 2026-10-27 12:17 UTCEG score recompute
  23. 2026-10-27 12:17 UTCVendor advisory
  24. 2026-10-27 12:17 UTCGHSA enrichmentGHSA-gmx7-j3pp-2gxp · GitHub severity CRITICAL · GitHub CVSS 9.8
  25. 2026-10-26 12:35 UTCVendor advisory
Show 74 more
  1. 2026-10-26 12:34 UTCGHSA enrichmentGHSA-gmx7-j3pp-2gxp · GitHub severity CRITICAL · GitHub CVSS 9.8
  2. 2026-10-25 19:26 UTCEG score recompute
  3. 2026-10-25 16:27 UTCEPSS rescoreEPSS 28% · 98th percentile
  4. 2026-10-25 12:47 UTCEG score recompute
  5. 2026-10-25 12:47 UTCVendor advisory
  6. 2026-10-25 12:46 UTCGHSA enrichmentGHSA-gmx7-j3pp-2gxp · GitHub severity CRITICAL · GitHub CVSS 9.8
  7. 2026-10-24 16:27 UTCEPSS rescoreEPSS 28% · 98th percentile
  8. 2026-10-24 13:00 UTCEG score recompute
  9. 2026-10-24 13:00 UTCVendor advisory
  10. 2026-10-24 13:00 UTCGHSA enrichmentGHSA-gmx7-j3pp-2gxp · GitHub severity CRITICAL · GitHub CVSS 9.8
  11. 2026-10-23 16:27 UTCEPSS rescoreEPSS 28% · 98th percentile
  12. 2026-10-23 13:16 UTCEG score recompute
  13. 2026-10-23 13:16 UTCVendor advisory
  14. 2026-10-23 13:16 UTCGHSA enrichmentGHSA-gmx7-j3pp-2gxp · GitHub severity CRITICAL · GitHub CVSS 9.8
  15. 2026-10-22 16:27 UTCEPSS rescoreEPSS 28% · 98th percentile
  16. 2026-10-22 13:29 UTCEG score recompute
  17. 2026-10-22 13:29 UTCVendor advisory
  18. 2026-10-22 13:29 UTCGHSA enrichmentGHSA-gmx7-j3pp-2gxp · GitHub severity CRITICAL · GitHub CVSS 9.8
  19. 2026-10-21 16:27 UTCEPSS rescoreEPSS 28% · 98th percentile
  20. 2026-10-21 13:44 UTCEG score recompute
  21. 2026-10-21 13:44 UTCVendor advisory
  22. 2026-10-21 13:44 UTCGHSA enrichmentGHSA-gmx7-j3pp-2gxp · GitHub severity CRITICAL · GitHub CVSS 9.8
  23. 2026-10-20 16:27 UTCEPSS rescoreEPSS 28% · 98th percentile
  24. 2026-10-20 14:01 UTCEG score recompute
  25. 2026-10-20 14:01 UTCVendor advisory
  26. 2026-10-20 14:01 UTCGHSA enrichmentGHSA-gmx7-j3pp-2gxp · GitHub severity CRITICAL · GitHub CVSS 9.8
  27. 2026-10-19 16:27 UTCEPSS rescoreEPSS 28% · 98th percentile
  28. 2026-10-19 13:12 UTCEG score recompute
  29. 2026-10-19 13:12 UTCVendor advisory
  30. 2026-10-19 13:12 UTCGHSA enrichmentGHSA-gmx7-j3pp-2gxp · GitHub severity CRITICAL · GitHub CVSS 9.8
  31. 2026-10-18 16:27 UTCEPSS rescoreEPSS 28% · 98th percentile
  32. 2026-10-18 12:08 UTCVendor advisory
  33. 2026-10-18 12:07 UTCGHSA enrichmentGHSA-gmx7-j3pp-2gxp · GitHub severity CRITICAL · GitHub CVSS 9.8
  34. 2026-10-18 10:21 UTCEG score recompute
  35. 2026-10-17 16:27 UTCEPSS rescoreEPSS 28% · 98th percentile
  36. 2026-10-17 11:12 UTCEG score recompute
  37. 2026-10-17 11:12 UTCVendor advisory
  38. 2026-10-17 11:12 UTCGHSA enrichmentGHSA-gmx7-j3pp-2gxp · GitHub severity CRITICAL · GitHub CVSS 9.8
  39. 2026-10-16 16:30 UTCEPSS rescoreEPSS 28% · 98th percentile
  40. 2026-10-16 11:26 UTCEG score recompute
  41. 2026-10-16 11:26 UTCVendor advisory
  42. 2026-10-16 11:26 UTCGHSA enrichmentGHSA-gmx7-j3pp-2gxp · GitHub severity CRITICAL · GitHub CVSS 9.8
  43. 2026-10-15 16:27 UTCEPSS rescoreEPSS 28% · 98th percentile
  44. 2026-10-15 11:41 UTCEG score recompute
  45. 2026-10-15 11:41 UTCVendor advisory
  46. 2026-10-15 11:41 UTCGHSA enrichmentGHSA-gmx7-j3pp-2gxp · GitHub severity CRITICAL · GitHub CVSS 9.8
  47. 2026-10-14 16:27 UTCEPSS rescoreEPSS 28% · 98th percentile
  48. 2026-10-14 07:13 UTCEG score recompute
  49. 2026-10-14 07:13 UTCVendor advisory
  50. 2026-10-14 07:12 UTCGHSA enrichmentGHSA-gmx7-j3pp-2gxp · GitHub severity CRITICAL · GitHub CVSS 9.8
  51. 2026-10-13 16:27 UTCEPSS rescoreEPSS 28% · 98th percentile
  52. 2026-10-13 02:29 UTCVendor advisory
  53. 2026-10-13 02:29 UTCGHSA enrichmentGHSA-gmx7-j3pp-2gxp · GitHub severity CRITICAL · GitHub CVSS 9.8
  54. 2026-10-12 20:20 UTCEG score recompute
  55. 2026-10-12 16:28 UTCEPSS rescoreEPSS 28% · 98th percentile
  56. 2026-10-12 00:43 UTCEG score recompute
  57. 2026-10-11 13:41 UTCEPSS rescoreEPSS 28% · 98th percentile
  58. 2026-10-10 19:55 UTCEPSS rescoreEPSS 28% · 98th percentile
  59. 2026-10-09 20:02 UTCEPSS rescoreEPSS 28% · 98th percentile
  60. 2026-10-08 16:36 UTCEPSS rescoreEPSS 28% · 98th percentile
  61. 2026-10-07 23:41 UTCEPSS rescoreEPSS 28% · 98th percentile
  62. 2026-10-06 15:12 UTCEPSS rescoreEPSS 28% · 98th percentile
  63. 2026-10-05 17:39 UTCEPSS rescoreEPSS 28% · 98th percentile
  64. 2026-10-03 14:21 UTCEPSS rescoreEPSS 28% · 98th percentile
  65. 2026-09-30 14:59 UTCEPSS rescoreEPSS 28% · 98th percentile
  66. 2026-09-30 09:52 UTCEG score recompute
  67. 2026-09-29 01:38 UTCOSV refresh
  68. 2026-09-28 13:45 UTCEPSS rescoreEPSS 28% · 98th percentile
  69. 2026-09-27 13:40 UTCEPSS rescoreEPSS 28% · 98th percentile
  70. 2026-09-26 15:53 UTCEPSS rescoreEPSS 28% · 98th percentile
  71. 2026-09-26 00:19 UTCEPSS rescoreEPSS 29% · 98th percentile
  72. 2026-09-24 13:59 UTCEPSS rescoreEPSS 29% · 98th percentile
  73. 2026-09-23 13:42 UTCEPSS rescoreEPSS 29% · 98th percentile
  74. 2026-09-21 20:27 UTCEPSS rescoreEPSS 24% · 97th percentile

Publicly available exploits

(1 reference)

Public exploit code is referenced for this CVE (1 Exploit-DB entry). Defenders should treat patch urgency accordingly.

  • Exploit-DBEDB-44909
    Published Jun 20, 2018

    ntp 4.2.8p11 - Local Buffer Overflow (PoC)

    Open source ↗

Frequently asked(5)

What is CVE-2018-12327?
CVE-2018-12327 is a critical-severity vulnerability; its CVE record was published on June 20, 2018. Stack-based buffer overflow in ntpq and ntpdc of NTP version 4.2.8p11 allows an attacker to achieve code execution or escalate to higher privileges via a long string as the argument for an IPv4 or IPv6 command-line parameter. NOTE: It is unclear whether there are any common situations in which ntpq…
When was CVE-2018-12327 made public?
CVE-2018-12327 was made public on June 20, 2018: that is the date its CVE record's CNA, MITRE Corporation, gives for when the vulnerability was made public. The CVE record itself was published on June 20, 2018. EchelonGraph's copy of the record carries a last-modified date of November 21, 2024; the record at its source may have been updated since.
Is CVE-2018-12327 actively exploited?
CVE-2018-12327 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 28% probability of exploitation in the next 30 days (98th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2018-12327?
CVE-2018-12327 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2018-12327?
A fix for CVE-2018-12327 is available: update to the fixed version the vendor names in its advisory.

Dependency Blast Radius

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