CVE-2020-27918

A use after free issue was addressed with improved memory management. This issue is fixed in macOS Big Sur 11.0.1, watchOS 7.1, iOS 14.2 and iPadOS 14.2, iCloud for Windows 11.5, Safari 14.0.1, tvOS 14.2, iTunes 12.11 for Windows. Processing maliciously crafted web content may lead to arbitrary code execution.

Published: 2020-12-08 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-27918 is rated Moderate Risk (45/100): CVSS High severity, with low exploitation likelihood (EPSS 0.18%). Review affected assets and schedule remediation.

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

Exploit prediction scoring system (EPSS) score for CVE-2020-27918

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 0.61% 0.18% -0.43%
2 2025-11-18 0.16% 0.61% +0.45%
3 2025-07-16 — 0.16% —

Full EPSS history (15 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-27918

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
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.
 1.8 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-2020-27918

OS Trackers for CVE-2020-27918

vendor priority summary link
alpine high CVE-2020-27918: 1 source package rows (webkit2gtk); 5 state rows across 5 repos (3.17-community, 3.18-community, 3.19-community, 3.20-community, edge-community); fixed 5, open 0. https://security.alpinelinux.org/vuln/CVE-2020-27918
debian not yet assigned CVE-2020-27918 not yet assigned priority: Debian including 2 source packages (webkit2gtk, wpewebkit), 10 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 10. https://security-tracker.debian.org/tracker/CVE-2020-27918
gentoo normal CVE-2020-27918: 1 GLSA(s) (202104-03), 1 atom(s) (net-libs/webkit-gtk); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2020-27918
redhat medium — https://access.redhat.com/security/cve/CVE-2020-27918
suse high CVE-2020-27918 severity important: SUSE including 236 source package names (LibRaw-0.19.5-3.el8, LibRaw-devel-0.19.5-3.el8, …), 543 product×package rows across 68 product lines (HPE Helion OpenStack 8, SUSE CaaS Platform 4.0, … (68 product lines)): Fixed 540, Known Not Affected 3. https://www.suse.com/security/cve/CVE-2020-27918/
ubuntu medium CVE-2020-27918 medium priority: Ubuntu including 5 source packages (qtwebkit-opensource-src, qtwebkit-source, webkit2gtk, webkitgtk, wpewebkit), 65 status rows across 13 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, trusty, upstream, xenial): DNE 29, ignored 22, released 11, needs-triage 3. https://ubuntu.com/security/CVE-2020-27918

Affected software / configurations for CVE-2020-27918

Vendor Product Version Raw CPE
apple icloud < 11.5 cpe:2.3:a:apple:icloud:*:*:*:*:*:windows:*:*
apple itunes < 12.11 cpe:2.3:a:apple:itunes:*:*:*:*:*:windows:*:*
apple safari < 14.0.1 cpe:2.3:a:apple:safari:*:*:*:*:*:*:*:*
apple ipados < 14.2 cpe:2.3:o:apple:ipados:*:*:*:*:*:*:*:*
apple iphone_os < 14.2 cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*
apple macos < 11.0.1 cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*
apple tvos < 14.2 cpe:2.3:o:apple:tvos:*:*:*:*:*:*:*:*
apple watchos < 7.1 cpe:2.3:o:apple:watchos:*:*:*:*:*:*:*:*
fedoraproject fedora 32 cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
fedoraproject fedora 33 cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
fedoraproject fedora 34 cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
webkitgtk webkitgtk\+ < 2.30.6 cpe:2.3:a:webkitgtk:webkitgtk\+:*:*:*:*:*:*:*:*

References for CVE-2020-27918

URL Tags
http://seclists.org/fulldisclosure/2020/Dec/32 Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/03/22/1 Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EQ3U3VBSOJB46WCO66TEWE5OAXLTU3YW/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JN6ZOD62CTO54CHTMJTHVEF6R2Y532TJ/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/L3L6ZZOU5JS7E3RFYGLP7UFLXCG7TNLU/
https://security.gentoo.org/glsa/202104-03 Third Party Advisory
https://support.apple.com/en-us/HT211928 Vendor Advisory
https://support.apple.com/en-us/HT211929 Vendor Advisory
https://support.apple.com/en-us/HT211930 Vendor Advisory
https://support.apple.com/en-us/HT211931 Vendor Advisory
https://support.apple.com/en-us/HT211933 Vendor Advisory
https://support.apple.com/en-us/HT211934 Vendor Advisory
https://support.apple.com/en-us/HT211935 Vendor Advisory
https://www.debian.org/security/2021/dsa-4877 Third Party Advisory
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