CVE-2021-30900
Published: 24 August 2021
Summary
CVE-2021-30900 is a high-severity Out-of-bounds Write (CWE-787) vulnerability in Apple Ipados. Its CVSS base score is 7.8 (High).
Operationally, ranked in the top 34.4% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog.
The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-2 (Flaw Remediation).
Deeper analysis
An out-of-bounds write vulnerability, tracked as CVE-2021-30900 and assigned CWE-787, affects iOS and iPadOS. The flaw stems from insufficient bounds checking and received a CVSS v3.1 score of 7.8. It is resolved in iOS 14.8.1, iPadOS 14.8.1, iOS 15.1, and iPadOS 15.1.
A malicious application running on an affected device can trigger the issue to perform an out-of-bounds write. Successful exploitation grants the attacker the ability to execute arbitrary code with kernel privileges. The attack requires local access, no prior privileges, and some user interaction.
Apple security advisories direct users to install the listed updates, which incorporate improved bounds checking to eliminate the flaw. The referenced support documents detail the affected builds and corresponding patched releases for both iOS and iPadOS.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2021-17817
Vulnerability details
An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 14.8.1 and iPadOS 14.8.1, iOS 15.1 and iPadOS 15.1. A malicious application may be able to execute arbitrary code with kernel privileges.
- CWE(s)
- KEV Date Added
- 30 March 2023
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly requires applying the vendor patches that add the improved bounds checking to eliminate the out-of-bounds write.
Mandates input validation and bounds checking that would have prevented the CWE-787 flaw allowing kernel-level code execution.
Requires memory-protection mechanisms that can block or contain exploitation of out-of-bounds writes to gain kernel privileges.