CVE-2020-27930
Memory Safety in Apple Watchos ≤ 5.3.9
Raw vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2020-27930 is a high-severity Out-of-bounds Write (CWE-787) vulnerability in Apple Watchos. Its CVSS base score is 7.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Security Account Manager (T1003.002); ranked in the top 2% 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 memory corruption vulnerability addressed through improved input validation affects font processing across multiple Apple platforms. The issue impacts macOS versions prior to Big Sur 11.0.1, Catalina 10.15.7 Supplemental Update, and Security Update 2020-006 for High Sierra and Mojave; iOS and iPadOS prior to 14.2 and 12.4.9; and watchOS prior to 7.1, 6.2.9, and 5.3.9. It is tracked as CWE-787 with a CVSS score of 7.8.
An attacker can trigger the flaw by supplying a maliciously crafted font file that the victim processes locally, such as by viewing a document or web page containing the font. Successful exploitation grants arbitrary code execution with the privileges of the affected process, though it requires user interaction to open the crafted content.
Apple security advisories for the listed updates, including HT211928, HT211929, and HT211931, direct users to install the available patches. Public references also include exploit artifacts posted to Packet Storm and Full Disclosure lists shortly after publication.
The references indicate at least one proof-of-concept targeting Safari via this vector, though no widespread in-the-wild exploitation is documented in the provided details.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2020-20423
Vulnerability Data
A memory corruption issue was addressed with improved input validation. 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. Processing a maliciously crafted font may lead to arbitrary code execution.
- CWE(s)
- KEV Date Added
- 03 November 2021
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Out-of-bounds writes that corrupt control flow or inject shellcode are rendered non-executable by the same memory protections.
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.
Vulnerability scanning and recording can discover out-of-bounds write flaws so they can be remediated.
Patching or replacing vulnerable software directly eliminates known instances of this coding weakness.
Secure-development practices (static analysis, bounds checking, code review) are the primary means of preventing out-of-bounds writes.
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.