CVE-2018-4233

HIGHNVD 8.88.9
EchelonGraph scoreHIGH confidence

“▲” beside the score: it is higher than NVD's CVSS score.

Score elevated to 8.9 because EPSS predicted 54% probability of exploitation within the next 30 days (99th percentile of EPSS-scored CVEs) when EchelonGraph scored this CVE. NVD baseline CVSS 8.8 retained for reference. Confidence: see factors.

Triggered by: EPSS exploit prediction (continuous uplift above 30%)
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3
Trending — 4 sources updated this weekWeaponized
8.9EG
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).
  • High exploitation likelihood — EPSS 54%
  • Public exploit code is available (Metasploit, Exploit-DB, marked verified by Exploit-DB, other public proof-of-concept code)
CISA-KEV: Not listedEPSS PROB: 54%CVSS: 8.8Exploit: Metasploit · Exploit-DB (verified) · other public PoCExposed services: Not assessed

A fix is available — apply it.

An issue was discovered in certain Apple products. iOS before 11.4 is affected. Safari before 11.1.1 is affected. iCloud before 7.5 on Windows is affected. iTunes before 12.7.5 on Windows is affected. tvOS before 11.4 is affected. watchOS before 4.3.1 is affected. The issue involves the "WebKit" component. It allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption and application crash) via a crafted web site.

CVSS v3
8.8
EG Score
8.9HIGHhigh confidence
EG Risk
66
EG Risk 66/100

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)
Severity88% × 45%
Impact severity (EG Severity): CVSS 8.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation65% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 2 (Weaponized): a constant, not a probability.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low, Track* at medium and Attend at high mission impact.
Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (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
54%
EPSS %ILE
99th
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 (8.9): severity, escalated by confirmed exploitation. This CVE's 8.9 is EPSS's lift toward 9.0 from its impact severity (EG Severity, CVSS 8.8 HIGH): a likelihood of exploitation, not impact.

EG Severity
8.8 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
54% within 30 daysSource: FIRST EPSS. 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: 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 (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (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.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). 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 8, 2018

Last Modified

November 21, 2024

Advisory Details (9)

Auto-updated Aug 13, 2026
Patch available.
Web page

About the security content of Safari 11.1.1 - Apple Support

https://support.apple.com/HT208854
Web page

About the security content of iCloud for Windows 7.5 - Apple Support

https://support.apple.com/HT208853
Web page

About the security content of iTunes 12.7.5 for Windows - Apple Support

https://support.apple.com/HT208852
Web page

About the security content of watchOS 4.3.1 - Apple Support

https://support.apple.com/HT208851
Web page

About the security content of tvOS 11.4 - Apple Support

https://support.apple.com/HT208850
Web page

About the security content of iOS 11.4 - Apple Support

https://support.apple.com/HT208848
Web page

WebkitGTK+: Multiple vulnerabilities (GLSA 201808-04) — Gentoo security

https://security.gentoo.org/glsa/201808-04

Patch Availability(1)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntuwebkit2gtk-driver (2.20.3-0ubuntu0.18.04.1) @ bionic2026-10-21ubuntu

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

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
webkit2gtk—
  • every version up to 2.20.3-1: fixed in 2.20.3-1
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
webkit2gtk—
  • every version up to 2.20.3-1: fixed in 2.20.3-1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
webkit2gtk—
  • every version up to 2.20.3-1: fixed in 2.20.3-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
webkit2gtk—
  • every version up to 2.20.3-1: fixed in 2.20.3-1
—

Weakness Classification(1)

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

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 11× in last 7d / 33× 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 89 of 126 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. 11 repeat rows among the latest 100 are merged into the row they repeat. The 37 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-23 16:27 UTCEPSS rescoreEPSS 54% · 99th percentile
  2. 2026-10-22 16:28 UTCEPSS rescoreEPSS 54% · 99th percentile
  3. 2026-10-21 19:46 UTCEG score recompute
  4. 2026-10-21 19:46 UTCVendor advisory
  5. 2026-10-21 19:46 UTCGHSA enrichmentGHSA-h77p-7p3g-477f · GitHub severity HIGH · GitHub CVSS 8.8
  6. 2026-10-21 16:27 UTCEPSS rescoreEPSS 54% · 99th percentile
  7. 2026-10-20 16:27 UTCEPSS rescoreEPSS 54% · 98th percentile
  8. 2026-10-19 16:27 UTCEPSS rescoreEPSS 54% · 98th percentile
  9. 2026-10-18 16:27 UTCEPSS rescoreEPSS 54% · 98th percentile
  10. 2026-10-18 10:08 UTCEG score recompute
  11. 2026-10-17 16:27 UTCEPSS rescoreEPSS 54% · 98th percentile
  12. 2026-10-16 16:30 UTCEPSS rescoreEPSS 54% · 98th percentile
  13. 2026-10-15 16:27 UTCEPSS rescoreEPSS 54% · 98th percentile
  14. 2026-10-14 16:27 UTCEPSS rescoreEPSS 54% · 98th percentile
  15. 2026-10-13 16:27 UTCEPSS rescoreEPSS 54% · 98th percentile
  16. 2026-10-13 02:06 UTCGHSA enrichmentGHSA-h77p-7p3g-477f · GitHub severity HIGH · GitHub CVSS 8.8
  17. 2026-10-12 20:10 UTCEG score recompute
  18. 2026-10-12 00:34 UTCEG score recompute
  19. 2026-10-11 13:41 UTCEPSS rescoreEPSS 54% · 98th percentile
  20. 2026-10-10 19:55 UTCEPSS rescoreEPSS 54% · 98th percentile
  21. 2026-10-09 20:03 UTCEPSS rescoreEPSS 54% · 98th percentile
  22. 2026-10-08 16:37 UTCEPSS rescoreEPSS 54% · 98th percentile
  23. 2026-10-07 23:42 UTCEPSS rescoreEPSS 54% · 98th percentile
  24. 2026-10-06 15:12 UTCEPSS rescoreEPSS 54% · 98th percentile
  25. 2026-10-04 23:18 UTCEPSS rescoreEPSS 54% · 98th percentile
Show 64 more
  1. 2026-10-03 14:21 UTCEPSS rescoreEPSS 53% · 98th percentile
  2. 2026-10-01 19:44 UTCEPSS rescoreEPSS 53% · 98th percentile
  3. 2026-09-30 14:59 UTCEPSS rescoreEPSS 53% · 98th percentile
  4. 2026-09-30 10:02 UTCEG score recompute
  5. 2026-09-29 02:08 UTCOSV refresh
  6. 2026-09-27 13:40 UTCEPSS rescoreEPSS 53% · 98th percentile
  7. 2026-09-26 15:53 UTCEPSS rescoreEPSS 53% · 98th percentile
  8. 2026-09-24 13:59 UTCEPSS rescoreEPSS 53% · 98th percentile
  9. 2026-09-23 13:42 UTCEPSS rescoreEPSS 53% · 98th percentile
  10. 2026-09-21 20:27 UTCEPSS rescoreEPSS 53% · 98th percentile
  11. 2026-09-19 15:36 UTCEPSS rescoreEPSS 53% · 98th percentile
  12. 2026-09-18 19:22 UTCEPSS rescoreEPSS 53% · 98th percentile
  13. 2026-09-17 19:22 UTCEPSS rescoreEPSS 53% · 98th percentile
  14. 2026-09-15 03:05 UTCEPSS rescoreEPSS 53% · 98th percentile
  15. 2026-09-11 14:48 UTCEPSS rescoreEPSS 53% · 98th percentile
  16. 2026-09-09 07:11 UTCOSV refresh
  17. 2026-09-06 13:44 UTCEPSS rescoreEPSS 53% · 98th percentile
  18. 2026-09-04 13:56 UTCEPSS rescoreEPSS 53% · 98th percentile
  19. 2026-09-02 14:07 UTCEPSS rescoreEPSS 53% · 98th percentile
  20. 2026-08-30 19:13 UTCEPSS rescoreEPSS 53% · 98th percentile
  21. 2026-08-30 01:18 UTCEPSS rescoreEPSS 53% · 98th percentile
  22. 2026-08-28 21:36 UTCEPSS rescoreEPSS 53% · 98th percentile
  23. 2026-08-26 14:42 UTCEPSS rescoreEPSS 53% · 98th percentile
  24. 2026-08-25 13:45 UTCEPSS rescoreEPSS 53% · 98th percentile
  25. 2026-08-24 14:11 UTCEPSS rescoreEPSS 53% · 98th percentile
  26. 2026-08-22 16:07 UTCOSV refresh
  27. 2026-08-21 23:45 UTCEPSS rescoreEPSS 53% · 98th percentile
  28. 2026-08-20 22:51 UTCEPSS rescoreEPSS 53% · 98th percentile
  29. 2026-08-19 17:00 UTCEPSS rescoreEPSS 53% · 98th percentile
  30. 2026-08-18 13:44 UTCEPSS rescoreEPSS 53% · 98th percentile
  31. 2026-08-17 13:43 UTCEPSS rescoreEPSS 53% · 98th percentile
  32. 2026-08-16 02:10 UTCEPSS rescoreEPSS 53% · 98th percentile
  33. 2026-08-15 01:26 UTCEPSS rescoreEPSS 53% · 98th percentile
  34. 2026-08-13 21:56 UTCEPSS rescoreEPSS 53% · 98th percentile
  35. 2026-08-12 13:47 UTCEPSS rescoreEPSS 54% · 98th percentile
  36. 2026-08-07 16:23 UTCEPSS rescoreEPSS 54% · 98th percentile
  37. 2026-08-06 20:05 UTCOSV refresh
  38. 2026-08-06 13:42 UTCEPSS rescoreEPSS 54% · 98th percentile
  39. 2026-07-30 16:24 UTCEPSS rescoreEPSS 54% · 98th percentile
  40. 2026-07-30 01:27 UTCEPSS rescoreEPSS 54% · 98th percentile
  41. 2026-07-28 15:32 UTCEPSS rescoreEPSS 54% · 98th percentile
  42. 2026-07-27 14:05 UTCEPSS rescoreEPSS 54% · 98th percentile
  43. 2026-07-26 14:51 UTCEPSS rescoreEPSS 54% · 98th percentile
  44. 2026-07-25 14:14 UTCEPSS rescoreEPSS 54% · 98th percentile
  45. 2026-07-24 14:14 UTCEPSS rescoreEPSS 54% · 98th percentile
  46. 2026-07-23 14:15 UTCEPSS rescoreEPSS 54% · 98th percentile
  47. 2026-07-23 01:36 UTCEG score recompute▲ 0.10
  48. 2026-07-22 22:16 UTCEG score recompute▼ 0.20
  49. 2026-07-22 14:05 UTCEPSS rescoreEPSS 54% · 98th percentile
  50. 2026-07-21 15:22 UTCEPSS rescoreEPSS 54% · 98th percentile
  51. 2026-07-21 11:47 UTCOSV refresh
  52. 2026-07-20 17:04 UTCEPSS rescoreEPSS 54% · 98th percentile
  53. 2026-07-19 02:26 UTCEPSS rescoreEPSS 54% · 98th percentile
  54. 2026-07-16 16:59 UTCEPSS rescoreEPSS 54% · 98th percentile
  55. 2026-07-15 16:55 UTCEPSS rescoreEPSS 54% · 98th percentile
  56. 2026-07-13 06:10 UTCEPSS rescoreEPSS 54% · 98th percentile
  57. 2026-07-12 05:43 UTCEPSS rescoreEPSS 54% · 98th percentile
  58. 2026-07-09 19:06 UTCEPSS rescoreEPSS 54% · 98th percentile
  59. 2026-07-05 02:27 UTCEPSS rescoreEPSS 54% · 98th percentile
  60. 2026-07-04 06:56 UTCOSV refresh
  61. 2026-07-01 15:03 UTCEPSS rescoreEPSS 54% · 98th percentile
  62. 2026-06-30 23:20 UTCEPSS rescoreEPSS 54% · 98th percentile
  63. 2026-06-28 04:53 UTCEPSS rescoreEPSS 54% · 98th percentile
  64. 2026-06-27 03:06 UTCEPSS rescoreEPSS 54% · 98th percentile

Publicly available exploits

(4 references)

Public exploit code is referenced for this CVE (2 Metasploit modules, 1 Exploit-DB entry, 1 GitHub PoC). Defenders should treat patch urgency accordingly.

  • Metasploitexploit/apple_ios/browser/webkit_createthis✓ verified
    Published Jun 2, 2019

    Safari Webkit Proxy Object Type Confusion

    Open source ↗
  • Exploit-DBEDB-45998✓ verified
    Published Dec 14, 2018

    Safari - Proxy Object Type Confusion (Metasploit)

    Open source ↗
  • Metasploitexploit/osx/browser/safari_proxy_object_type_confusion✓ verified
    Published Dec 13, 2018

    Safari Proxy Object Type Confusion

    Open source ↗
  • GitHub PoCsaelo/cve-2018-4233
    Published Aug 8, 2018

    Exploit for CVE-2018-4233, a WebKit JIT optimization bug used during Pwn2Own 2018

    Open source ↗

Frequently asked(5)

What is CVE-2018-4233?
CVE-2018-4233 is a high-severity vulnerability; its CVE record was published on June 8, 2018. An issue was discovered in certain Apple products. iOS before 11.4 is affected. Safari before 11.1.1 is affected. iCloud before 7.5 on Windows is affected. iTunes before 12.7.5 on Windows is affected. tvOS before 11.4 is affected. watchOS before 4.3.1 is affected. The issue involves the "WebKit"…
When was CVE-2018-4233 made public?
CVE-2018-4233 was made public on June 1, 2018: that is the date its CVE record's CNA, Apple Inc., gives for when the vulnerability was made public. The CVE record itself was published on June 8, 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-2018-4233 actively exploited?
CVE-2018-4233 is not currently on CISA's Known Exploited Vulnerabilities catalog. EchelonGraph's EG-KEV model places it in Tier 2 (Weaponized), which is not evidence of exploitation: a Metasploit module exists for it, and Exploit-DB marks a public exploit for it as verified, and CISA's SSVC data says a public PoC exists and its EPSS is 50% or more. EchelonGraph does not test whether exploit code works. FIRST EPSS estimates a 54% probability of exploitation in the next 30 days (99th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2018-4233?
CVE-2018-4233 has a CVSS v3 base score of 8.8 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 8.9 (HIGH).
How do I remediate CVE-2018-4233?
A fix for CVE-2018-4233 is available: update to the fixed version the vendor names in its advisory.

Dependency Blast Radius

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