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.
CVE-2018-4233
“▲” 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.
- High exploitation likelihood — EPSS 54%
- Public exploit code is available (Metasploit, Exploit-DB, marked verified by Exploit-DB, other public proof-of-concept code)
A fix is available — apply it.
- CVSS v3
- 8.8
- EG Score
- 8.9HIGHhigh confidence
- EG Risk
- 66EG 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, 2026About the security content of Safari 11.1.1 - Apple Support
https://support.apple.com/HT208854About the security content of iCloud for Windows 7.5 - Apple Support
https://support.apple.com/HT208853About the security content of iTunes 12.7.5 for Windows - Apple Support
https://support.apple.com/HT208852About the security content of watchOS 4.3.1 - Apple Support
https://support.apple.com/HT208851WebkitGTK+: Multiple vulnerabilities (GLSA 201808-04) — Gentoo security
https://security.gentoo.org/glsa/201808-04Packet Storm Security
http://packetstormsecurity.com/files/153148/Safari-Webkit-Proxy-Object-Type-Confusion.htmlPatch Availability(1)
| Vendor / Ecosystem | Fix (by version range) / Patch | Released | Source |
|---|---|---|---|
| ubuntu | webkit2gtk-driver (2.20.3-0ubuntu0.18.04.1) @ bionic | 2026-10-21 | ubuntu |
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)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| webkit2gtk | — |
| — |
Debian:12(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| webkit2gtk | — |
| — |
Debian:13(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| webkit2gtk | — |
| — |
Debian:14(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| webkit2gtk | — |
| — |
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.
- 2026-10-23 16:27 UTCEPSS rescoreEPSS 54% · 99th percentile
- 2026-10-22 16:28 UTCEPSS rescoreEPSS 54% · 99th percentile
- 2026-10-21 19:46 UTCEG score recompute
- 2026-10-21 19:46 UTCVendor advisory
- 2026-10-21 19:46 UTCGHSA enrichmentGHSA-h77p-7p3g-477f · GitHub severity HIGH · GitHub CVSS 8.8
- 2026-10-21 16:27 UTCEPSS rescoreEPSS 54% · 99th percentile
- 2026-10-20 16:27 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-10-19 16:27 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-10-18 16:27 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-10-18 10:08 UTCEG score recompute
- 2026-10-17 16:27 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-10-16 16:30 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-10-15 16:27 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-10-14 16:27 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-10-13 16:27 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-10-13 02:06 UTCGHSA enrichmentGHSA-h77p-7p3g-477f · GitHub severity HIGH · GitHub CVSS 8.8
- 2026-10-12 20:10 UTCEG score recompute
- 2026-10-12 00:34 UTCEG score recompute
- 2026-10-11 13:41 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-10-10 19:55 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-10-09 20:03 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-10-08 16:37 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-10-07 23:42 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-10-06 15:12 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-10-04 23:18 UTCEPSS rescoreEPSS 54% · 98th percentile
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- 2026-10-03 14:21 UTCEPSS rescoreEPSS 53% · 98th percentile
- 2026-10-01 19:44 UTCEPSS rescoreEPSS 53% · 98th percentile
- 2026-09-30 14:59 UTCEPSS rescoreEPSS 53% · 98th percentile
- 2026-09-30 10:02 UTCEG score recompute
- 2026-09-29 02:08 UTCOSV refresh
- 2026-09-27 13:40 UTCEPSS rescoreEPSS 53% · 98th percentile
- 2026-09-26 15:53 UTCEPSS rescoreEPSS 53% · 98th percentile
- 2026-09-24 13:59 UTCEPSS rescoreEPSS 53% · 98th percentile
- 2026-09-23 13:42 UTCEPSS rescoreEPSS 53% · 98th percentile
- 2026-09-21 20:27 UTCEPSS rescoreEPSS 53% · 98th percentile
- 2026-09-19 15:36 UTCEPSS rescoreEPSS 53% · 98th percentile
- 2026-09-18 19:22 UTCEPSS rescoreEPSS 53% · 98th percentile
- 2026-09-17 19:22 UTCEPSS rescoreEPSS 53% · 98th percentile
- 2026-09-15 03:05 UTCEPSS rescoreEPSS 53% · 98th percentile
- 2026-09-11 14:48 UTCEPSS rescoreEPSS 53% · 98th percentile
- 2026-09-09 07:11 UTCOSV refresh
- 2026-09-06 13:44 UTCEPSS rescoreEPSS 53% · 98th percentile
- 2026-09-04 13:56 UTCEPSS rescoreEPSS 53% · 98th percentile
- 2026-09-02 14:07 UTCEPSS rescoreEPSS 53% · 98th percentile
- 2026-08-30 19:13 UTCEPSS rescoreEPSS 53% · 98th percentile
- 2026-08-30 01:18 UTCEPSS rescoreEPSS 53% · 98th percentile
- 2026-08-28 21:36 UTCEPSS rescoreEPSS 53% · 98th percentile
- 2026-08-26 14:42 UTCEPSS rescoreEPSS 53% · 98th percentile
- 2026-08-25 13:45 UTCEPSS rescoreEPSS 53% · 98th percentile
- 2026-08-24 14:11 UTCEPSS rescoreEPSS 53% · 98th percentile
- 2026-08-22 16:07 UTCOSV refresh
- 2026-08-21 23:45 UTCEPSS rescoreEPSS 53% · 98th percentile
- 2026-08-20 22:51 UTCEPSS rescoreEPSS 53% · 98th percentile
- 2026-08-19 17:00 UTCEPSS rescoreEPSS 53% · 98th percentile
- 2026-08-18 13:44 UTCEPSS rescoreEPSS 53% · 98th percentile
- 2026-08-17 13:43 UTCEPSS rescoreEPSS 53% · 98th percentile
- 2026-08-16 02:10 UTCEPSS rescoreEPSS 53% · 98th percentile
- 2026-08-15 01:26 UTCEPSS rescoreEPSS 53% · 98th percentile
- 2026-08-13 21:56 UTCEPSS rescoreEPSS 53% · 98th percentile
- 2026-08-12 13:47 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-08-07 16:23 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-08-06 20:05 UTCOSV refresh
- 2026-08-06 13:42 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-07-30 16:24 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-07-30 01:27 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-07-28 15:32 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-07-27 14:05 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-07-26 14:51 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-07-25 14:14 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-07-24 14:14 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-07-23 14:15 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-07-23 01:36 UTCEG score recompute▲ 0.10
- 2026-07-22 22:16 UTCEG score recompute▼ 0.20
- 2026-07-22 14:05 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-07-21 15:22 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-07-21 11:47 UTCOSV refresh
- 2026-07-20 17:04 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-07-19 02:26 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-07-16 16:59 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-07-15 16:55 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-07-13 06:10 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-07-12 05:43 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-07-09 19:06 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-07-05 02:27 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-07-04 06:56 UTCOSV refresh
- 2026-07-01 15:03 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-06-30 23:20 UTCEPSS rescoreEPSS 54% · 98th percentile
- 2026-06-28 04:53 UTCEPSS rescoreEPSS 54% · 98th percentile
- 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✓ verifiedPublished Jun 2, 2019
Safari Webkit Proxy Object Type Confusion
Open source ↗ - Exploit-DBEDB-45998✓ verifiedPublished Dec 14, 2018
Safari - Proxy Object Type Confusion (Metasploit)
Open source ↗ - Metasploitexploit/osx/browser/safari_proxy_object_type_confusion✓ verifiedPublished Dec 13, 2018
Safari Proxy Object Type Confusion
Open source ↗ - GitHub PoCsaelo/cve-2018-4233Published Aug 8, 2018
Exploit for CVE-2018-4233, a WebKit JIT optimization bug used during Pwn2Own 2018
Open source ↗
Related CVEs(same vendor + same CWE)
Same vendor
6 shownubuntu:USN-3687-1
Frequently asked(5)
What is CVE-2018-4233?
When was CVE-2018-4233 made public?
Is CVE-2018-4233 actively exploited?
What is the CVSS score of CVE-2018-4233?
How do I remediate CVE-2018-4233?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2018-4233
Is Your Infrastructure Affected by CVE-2018-4233?
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