Cyber Resilience

CVE-2020-27932

Memory Safety in Apple Watchos ≤ 5.3.9

CISA KEVActive ExploitationEUVD ExploitedPublic PoCMemory Safety
Published
08 December 2020
Modified
27 October 2025
KEV Added
03 November 2021
Patch / advisory
View advisory
CVSS Score v3.1 7.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.10 95th percentile
Risk Priority 83 floored blend · peak EPSS

Summary

CVE-2020-27932 is a high-severity Type Confusion (CWE-843) vulnerability in Apple Watchos. Its CVSS base score is 7.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 5% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog; a public proof-of-concept is referenced.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

A type confusion vulnerability, identified as CWE-843, was present in the XNU kernel and addressed through improved state handling. It affected multiple Apple platforms, including macOS Big Sur prior to 11.0.1, macOS Catalina prior to the 10.15.7 Supplemental Update, macOS Mojave and High Sierra prior to Security Update 2020-006, iOS prior to 14.2 and 12.4.9, iPadOS prior to 14.2, and various watchOS releases up to 7.1, 6.2.9, and 5.3.9.

The flaw could be triggered by a malicious application running on the device. With local access and no privileges required beyond user interaction to launch the app, an attacker could achieve arbitrary code execution with full kernel privileges, resulting in complete system compromise.

Apple security advisories for the listed updates, including HT211928, HT211929, and HT211931, recommend installing the patches that resolve the issue in the affected operating systems. Public references also include exploit details posted to sites such as Packet Storm and Full Disclosure.

EU & UK References

Vulnerability Data

A type confusion issue was addressed with improved state handling. This issue is fixed in macOS Big Sur 11.0.1, watchOS 7.1, iOS 12.4.9, watchOS 6.2.9, Security Update 2020-006 High Sierra, Security Update 2020-006 Mojave, iOS 14.2 and iPadOS 14.2, watchOS…

more

5.3.9, macOS Catalina 10.15.7 Supplemental Update, macOS Catalina 10.15.7 Update. A malicious application may be able to execute arbitrary code with kernel privileges.

CWE(s)
CWE-843
KEV Date Added
03 November 2021

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2021-30869Same product: Apple Ipadosboth on KEV
CVE-2023-23529Same product: Apple Ipadosboth on KEV
CVE-2022-42856Same product: Apple Ipadosboth on KEV
CVE-2024-23222Same product: Apple Ipadosboth on KEV
CVE-2020-27930Same product: Apple Ipadosboth on KEV
CVE-2021-31010Same product: Apple Ipadosboth on KEV
CVE-2021-1789Same product: Apple Ipadosboth on KEV
CVE-2023-27930Same product: Apple Ipados
CVE-2023-32434Same product: Apple Ipadosboth on KEV
CVE-2019-8506Same product: Apple Icloudboth on KEV

Affected Assets

apple
icloud
≤ 11.5
apple
itunes
≤ 12.11
apple
ipados
≤ 14.2
apple
iphone os
≤ 12.4.9 · 14.0 — 14.2
apple
mac os x
≤ 10.15.7
apple
macos
11.0 — 11.0.1
apple
watchos
≤ 5.3.9 · 6.0 — 6.2.9 · 7.0 — 7.1

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V1.5.2
  • V3.2.3
  • V15.3.5

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly prevent type-confusion flaws via safe typing, static analysis, and code review while the control itself addresses many additional weaknesses.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development can detect type-confusion vulnerabilities through fuzzing and static analysis.

A.8.25 Secure development life cycle partial match
prevents

Secure SDLC mandates type-safe design and review that can catch type-confusion flaws.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify strong typing and interface contracts that reduce type confusion.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles promote type-safe languages and memory-safety mechanisms that mitigate type confusion.

A.8.28 Secure coding partial match
prevents

Secure coding standards directly forbid unsafe type casts and require static-analysis checks for type confusion.

References