Out-of-Bounds Write in Apple Mail (CVE‑2020‑9818) Risks iOS, iPadOS, and watchOS Devices
What It Is – An out‑of‑bounds write flaw in the Mail app of Apple iOS, iPadOS, and watchOS can corrupt memory or crash the application when a maliciously‑crafted email is processed.
Exploitability – Publicly disclosed; no known active exploit in the wild, but the vulnerability is rated CVSS 3.1 7.5 (High), indicating a realistic risk if an attacker can deliver a crafted message.
Affected Products – Apple iOS 13.5 and earlier, iPadOS 13.5 and earlier, watchOS 6.5 and earlier (Mail component).
Why It Matters for Trust & Control Assurance
- Demonstrates the need for a vulnerability‑management control that ensures timely identification and remediation of known flaws.
- Provides audit‑ready evidence that an organization’s patch‑management process is operating effectively – a key control across SOC 2, ISO 27001, NIST CSF, and many others.
- Highlights the importance of continuous monitoring of device fleets to prove due‑diligence to regulators and enterprise partners.
Recommended Actions
- Verify all iOS, iPadOS, and watchOS devices are running the latest OS version that includes the CVE‑2020‑9818 fix.
- Use an MDM solution to enforce mandatory OS updates across the device inventory.
- Capture and retain proof‑of‑patch (e.g., compliance reports, screenshot logs) for audit purposes.
- Review mail‑processing policies and consider disabling HTML rendering for untrusted messages until patches are confirmed.
Source: CISA KEV – CVE‑2020‑9818