CVE-2020-9951

A use after free issue was addressed with improved memory management. This issue is fixed in Safari 14.0. Processing maliciously crafted web content may lead to arbitrary code execution.

Published: 2020-10-16 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-9951 is rated Moderate Risk (63.7/100): CVSS High severity, with medium exploitation likelihood (EPSS 2.25%). 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-2020-9951

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 2026-06-15 1.99% 2.25% +0.26%
2 2025-12-03 1.15% 1.99% +0.85%
3 2025-11-21 — 1.15% —

Full EPSS history (15 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-9951

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.1 HIGH
CVSS:3.1/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-2020-9951

OS Trackers for CVE-2020-9951

vendor priority summary link
alpine high CVE-2020-9951: 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-2020-9951
debian not yet assigned CVE-2020-9951 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-2020-9951
gentoo normal CVE-2020-9951: 1 GLSA(s) (202012-10), 1 atom(s) (net-libs/webkit-gtk); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2020-9951
redhat medium — https://access.redhat.com/security/cve/CVE-2020-9951
suse high CVE-2020-9951 severity important: SUSE including 185 source package names (WebKit2GTK-4.1-lang-2.36.0-150400.2.13, WebKit2GTK-5.0-lang-2.36.0-150400.2.12, …), 470 product×package rows across 66 product lines (HPE Helion OpenStack 8, SUSE CaaS Platform 4.0, … (66 product lines)): Fixed 467, Known Not Affected 3. https://www.suse.com/security/cve/CVE-2020-9951/
ubuntu medium CVE-2020-9951 medium priority: Ubuntu including 6 source packages (qtwebkit, qtwebkit-opensource-src, qtwebkit-source, webkit2gtk, webkitgtk, wpewebkit), 78 status rows across 13 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, trusty, upstream, xenial): DNE 41, ignored 18, not-affected 12, needs-triage 4, released 3. https://ubuntu.com/security/CVE-2020-9951

Affected software / configurations for CVE-2020-9951

Vendor Product Version Raw CPE
apple icloud < 11.5 cpe:2.3:a:apple:icloud:*:*:*:*:*:windows:*:*
apple itunes < 12.10.9 cpe:2.3:a:apple:itunes:*:*:*:*:*:windows:*:*
apple safari < 14.0 cpe:2.3:a:apple:safari:*:*:*:*:*:*:*:*
apple ipados < 14.0 cpe:2.3:o:apple:ipados:*:*:*:*:*:*:*:*
apple iphone_os < 14.0 cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*
apple tvos < 14.0 cpe:2.3:o:apple:tvos:*:*:*:*:*:*:*:*
apple watchos < 7.0 cpe:2.3:o:apple:watchos:*:*:*:*:*:*:*:*
webkit webkitgtk\+ <= 2.30.3 cpe:2.3:a:webkit:webkitgtk\+:*:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*

References for CVE-2020-9951

URL Tags
http://seclists.org/fulldisclosure/2020/Nov/18 Mailing List Third Party Advisory
http://seclists.org/fulldisclosure/2020/Nov/19 Mailing List Third Party Advisory
http://seclists.org/fulldisclosure/2020/Nov/20 Mailing List Third Party Advisory
http://seclists.org/fulldisclosure/2020/Nov/22 Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2020/11/23/3 Mailing List Third Party Advisory
https://security.gentoo.org/glsa/202012-10 Third Party Advisory
https://support.apple.com/HT211845 Release Notes Vendor Advisory
https://support.apple.com/kb/HT211843 Vendor Advisory
https://support.apple.com/kb/HT211844 Vendor Advisory
https://support.apple.com/kb/HT211850 Vendor Advisory
https://support.apple.com/kb/HT211935 Vendor Advisory
https://support.apple.com/kb/HT211952 Vendor Advisory
https://www.debian.org/security/2020/dsa-4797 Third Party Advisory
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