NVD / CVE Program· CNA apple

CVE-2021-1788: A use after free issue was addressed with improved memory management.

Noroxi assessment

Priority: Monitor (action score 36/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 1.6% (FIRST EPSS); higher than 77% of all records.
Anyone who can reach it over the internet can trigger it. No account or password is required. A user must open a link or visit a page. No special conditions are required; it is repeatable.
Fixed version: accountsservice (AlmaLinux:8) 0.6.55-2.el8; accountsservice-devel (AlmaLinux:8) 0.6.55-2.el8; accountsservice-libs (AlmaLinux:8) 0.6.55-2.el8.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to accountsservice (AlmaLinux:8) 0.6.55-2.el8; accountsservice-devel (AlmaLinux:8) 0.6.55-2.el8; accountsservice-libs (AlmaLinux:8) 0.6.55-2.el8 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

A use after free issue was addressed with improved memory management. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, tvOS 14.4, watchOS 7.3, iOS 14.4 and iPadOS 14.4, Safari 14.0.3. Processing maliciously crafted web content may lead to arbitrary code execution.

HighCVSS 8.8 · v3.1—No exploit Fix available

Published: Apr 2, 2021
Updated: Jun 16, 2026
EPSS: 1.6% · 77th percentile
CWE: CWE-416

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 35 / 40 · 8.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 1 / 30 · 1.6%

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
apple	ipados	cpe:2.3:o:apple:ipados
apple	iphone os	cpe:2.3:o:apple:iphone_os
apple	mac os x	cpe:2.3:o:apple:mac_os_x
apple	macos	cpe:2.3:o:apple:macos
apple	safari	cpe:2.3:o:apple:safari
apple	tvos	cpe:2.3:o:apple:tvos
apple	watchos	cpe:2.3:o:apple:watchos
debian	debian linux	cpe:2.3:o:debian:debian_linux
fedoraproject	fedora	cpe:2.3:o:fedoraproject:fedora

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

apple ipadosbefore 14.4
apple iphone osbefore 14.4
apple mac os x10.14 and later · before 10.14.6
apple mac os x10.15 and later · before 10.15.7
apple mac os x10.14.6
apple mac os x10.15.7
apple macos11.0 and later · before 11.2
apple safaribefore 14.0.3
apple tvosbefore 14.4
apple watchosbefore 7.3
debian debian linux10.0
fedoraproject fedora33

Versions reported by the vendor

Affected version ranges reported by the assigning authority (apple). Independent of NVD's CPE analysis and usually ahead of it.

Apple iOS and iPadOS
- unspecified and later · before 14.4affected
Apple macOS
- unspecified and later · before 11.2affected
- unspecified and later · before 7.3affected
- unspecified and later · before 14.4affected
- unspecified and later · before 14.0affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
AlmaLinux:8	accountsservice	before 0.6.55-2.el8	0.6.55-2.el8
AlmaLinux:8	accountsservice-devel	before 0.6.55-2.el8	0.6.55-2.el8
AlmaLinux:8	accountsservice-libs	before 0.6.55-2.el8	0.6.55-2.el8
AlmaLinux:8	gdm	before 1:40.0-15.el8	1:40.0-15.el8
AlmaLinux:8	gnome-autoar	before 0.2.3-2.el8	0.2.3-2.el8
AlmaLinux:8	gnome-calculator	before 3.28.2-2.el8	3.28.2-2.el8
AlmaLinux:8	gnome-classic-session	before 3.32.1-20.el8	3.32.1-20.el8
AlmaLinux:8	gnome-control-center	before 3.28.2-28.el8	3.28.2-28.el8
AlmaLinux:8	gnome-control-center-filesystem	before 3.28.2-28.el8	3.28.2-28.el8
AlmaLinux:8	gnome-online-accounts	before 3.28.2-3.el8	3.28.2-3.el8
AlmaLinux:8	gnome-online-accounts-devel	before 3.28.2-3.el8	3.28.2-3.el8
AlmaLinux:8	gnome-session	before 3.28.1-13.el8	3.28.1-13.el8
AlmaLinux:8	gnome-session-kiosk-session	before 3.28.1-13.el8	3.28.1-13.el8
AlmaLinux:8	gnome-session-wayland-session	before 3.28.1-13.el8	3.28.1-13.el8
AlmaLinux:8	gnome-session-xsession	before 3.28.1-13.el8	3.28.1-13.el8
AlmaLinux:8	gnome-settings-daemon	before 3.32.0-16.el8.alma	3.32.0-16.el8.alma
AlmaLinux:8	gnome-shell	before 3.32.2-40.el8	3.32.2-40.el8
AlmaLinux:8	gnome-shell-extension-apps-menu	before 3.32.1-20.el8	3.32.1-20.el8
AlmaLinux:8	gnome-shell-extension-auto-move-windows	before 3.32.1-20.el8	3.32.1-20.el8
AlmaLinux:8	gnome-shell-extension-common	before 3.32.1-20.el8	3.32.1-20.el8
AlmaLinux:8	gnome-shell-extension-dash-to-dock	before 3.32.1-20.el8	3.32.1-20.el8
AlmaLinux:8	gnome-shell-extension-desktop-icons	before 3.32.1-20.el8	3.32.1-20.el8
AlmaLinux:8	gnome-shell-extension-disable-screenshield	before 3.32.1-20.el8	3.32.1-20.el8
AlmaLinux:8	gnome-shell-extension-drive-menu	before 3.32.1-20.el8	3.32.1-20.el8

+78

Same product

apple: all records

Other highest-scoring records for the same primary product.

CVE-2025-43300An out-of-bounds write issue was addressed with improved bounds checking.KEV
90Now
CVE-2021-30860An integer overflow was addressed with improved input validation.KEV
84Now
CVE-2023-32434An integer overflow was addressed with improved input validation.KEV
78This week

Published before and after this one in the same product

← EarlierCVE-2021-1786Apr 2, 2021 · A logic issue was addressed with improved state management.
22Monitor
← EarlierCVE-2021-1787Apr 2, 2021 · Multiple issues were addressed with improved logic.
31Monitor
Later →CVE-2021-1789Apr 2, 2021 · A type confusion issue was addressed with improved state handling.KEV
69This week

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
almalinux:accountsservice	0.6.55-2.el8 · AlmaLinux:8	Package registry (OSV)
almalinux:accountsservice-devel	0.6.55-2.el8 · AlmaLinux:8	Package registry (OSV)
almalinux:accountsservice-libs	0.6.55-2.el8 · AlmaLinux:8	Package registry (OSV)
almalinux:gdm	1:40.0-15.el8 · AlmaLinux:8	Package registry (OSV)
almalinux:gnome-autoar	0.2.3-2.el8 · AlmaLinux:8	Package registry (OSV)
almalinux:gnome-calculator	3.28.2-2.el8 · AlmaLinux:8	Package registry (OSV)
almalinux:gnome-classic-session	3.32.1-20.el8 · AlmaLinux:8	Package registry (OSV)
almalinux:gnome-control-center	3.28.2-28.el8 · AlmaLinux:8	Package registry (OSV)
almalinux:gnome-control-center-filesystem	3.28.2-28.el8 · AlmaLinux:8	Package registry (OSV)
almalinux:gnome-online-accounts	3.28.2-3.el8 · AlmaLinux:8	Package registry (OSV)
almalinux:LibRaw	0.19.5-3.el8 · AlmaLinux:8	Package registry (OSV)
almalinux:LibRaw-devel	0.19.5-3.el8 · AlmaLinux:8	Package registry (OSV)
alpine:webkit2gtk	2.32.0-r0 · Alpine:v3.13	Package registry (OSV)
debian:webkit2gtk	2.32.0-2 · Debian:12	Package registry (OSV)
debian:wpewebkit	2.32.0-2 · Debian:12	Package registry (OSV)
opensuse:webkit2gtk3	2.32.0-lp152.2.13.1 · openSUSE:Leap 15.2	Package registry (OSV)
red hat:LibRaw	0:0.19.5-3.el8 · Red Hat:enterprise_linux:8::appstream	Package registry (OSV)
red hat:LibRaw-debuginfo	0:0.19.5-3.el8 · Red Hat:enterprise_linux:8::appstream	Package registry (OSV)
red hat:LibRaw-debugsource	0:0.19.5-3.el8 · Red Hat:enterprise_linux:8::appstream	Package registry (OSV)
red hat:webkit2gtk3	0:2.32.3-2.el8 · Red Hat:enterprise_linux:8::appstream	Package registry (OSV)
red hat:webkit2gtk3-debuginfo	0:2.32.3-2.el8 · Red Hat:enterprise_linux:8::appstream	Package registry (OSV)
red hat:webkit2gtk3-debugsource	0:2.32.3-2.el8 · Red Hat:enterprise_linux:8::appstream	Package registry (OSV)
red hat:webkit2gtk3-devel	0:2.32.3-2.el8 · Red Hat:enterprise_linux:8::appstream	Package registry (OSV)
red hat:webkit2gtk3-devel-debuginfo	0:2.32.3-2.el8 · Red Hat:enterprise_linux:8::appstream	Package registry (OSV)
red hat:webkit2gtk3-jsc	0:2.32.3-2.el8 · Red Hat:enterprise_linux:8::appstream	Package registry (OSV)
red hat:webkit2gtk3-jsc-debuginfo	0:2.32.3-2.el8 · Red Hat:enterprise_linux:8::appstream	Package registry (OSV)
red hat:webkit2gtk3-jsc-devel	0:2.32.3-2.el8 · Red Hat:enterprise_linux:8::appstream	Package registry (OSV)
red hat:webkit2gtk3-jsc-devel-debuginfo	0:2.32.3-2.el8 · Red Hat:enterprise_linux:8::appstream	Package registry (OSV)
rocky linux:accountsservice	0:0.6.55-2.el8 · Rocky Linux:8	Package registry (OSV)
rocky linux:gdm	1:40.0-15.el8 · Rocky Linux:8	Package registry (OSV)

+11

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

TR-21-0431 · Jun 1, 2021(Debian Güvenlik Güncellemesi Yayınladı)

All national notices →

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
A user must open a link or visit a page.
No special conditions are required; it is repeatable.

If successful

Confidentiality: high · data can be read
Integrity: high · data or configuration can be modified
Availability: high · the service can be disrupted

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: Required
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

nvd-primary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1free(dev->buf);
2/* ... another thread is still running ... */
3process(dev->buf);

Fixed

1lock(&dev->lock);
2free(dev->buf);
3dev->buf = NULL;
4unlock(&dev->lock);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

Fix✗ → ✓Sep 28, 2026, 10:46 PM UTC

For records you follow, these changes also arrive as notifications. →

References

lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/L3L6ZZOU5JS7E3RFYGLP7UFLXCG7TNLU/

Show all references (6 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records