CVE-2018-4121

Exp

An issue was discovered in certain Apple products. iOS before 11.3 is affected. Safari before 11.1 is affected. iCloud before 7.4 on Windows is affected. iTunes before 12.7.4 on Windows is affected. tvOS before 11.3 is affected. watchOS before 4.3 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.

Published: 2018-04-03 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2018-4121 is rated High Exploit Risk (83.7/100): CVSS High severity, with high exploitation likelihood (EPSS 38.61%, 97th percentile). 3 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2018-4121

EDB-ID Source Kind Published Link
44427 exploit_db edb 2018-04-09 Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2018-4121

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-11-21 39.04% 38.61% -0.43%
2 2025-11-18 38.61% 39.04% +0.43%
3 2025-10-18 — 38.61% —

Full EPSS history (26 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2018-4121

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.0 HIGH
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 5.9 [email protected]
6.8 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 6.4 [email protected]

Weakness enumeration for CVE-2018-4121

OS Trackers for CVE-2018-4121

vendor priority summary link
debian unimportant CVE-2018-4121 unimportant priority: Debian including 1 source packages (webkit2gtk), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2018-4121
gentoo normal CVE-2018-4121: 1 GLSA(s) (201808-04), 1 atom(s) (net-libs/webkit-gtk); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2018-4121
redhat medium — https://access.redhat.com/security/cve/CVE-2018-4121
suse medium CVE-2018-4121 severity moderate: SUSE including 439 source package names (PackageKit-1.1.10-1.el7, PackageKit-command-not-found-1.1.10-1.el7, …), 485 product×package rows across 15 product lines (SUSE Liberty Linux 7 LTSS, SUSE Linux Enterprise Desktop 12 SP3, … (15 product lines)): Fixed 485. https://www.suse.com/security/cve/CVE-2018-4121/
ubuntu medium CVE-2018-4121 medium priority: Ubuntu including 5 source packages (qtwebkit, qtwebkit-opensource-src, qtwebkit-source, webkit2gtk, webkitgtk), 83 status rows across 17 suites (artful, bionic, cosmic, disco, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, trusty, upstream, xenial): DNE 38, ignored 26, not-affected 13, needs-triage 3, released 3. https://ubuntu.com/security/CVE-2018-4121

Affected software / configurations for CVE-2018-4121

Vendor Product Version Raw CPE
apple safari < 11.1 cpe:2.3:a:apple:safari:*:*:*:*:*:*:*:*
apple iphone_os < 11.3 cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*
apple tvos < 11.3 cpe:2.3:o:apple:tvos:*:*:*:*:*:*:*:*
apple watchos < 4.3 cpe:2.3:o:apple:watchos:*:*:*:*:*:*:*:*
apple icloud < 7.4 cpe:2.3:a:apple:icloud:*:*:*:*:*:*:*:*
apple itunes < 12.7.4 cpe:2.3:a:apple:itunes:*:*:*:*:*:*:*:*

References for CVE-2018-4121

cvelogic Threat Intelligence