Security readout for executives and security teams
Plain-English summary
This Apple iOS/iPadOS kernel flaw can let a malicious app gain kernel-level code execution on vulnerable iPhones or iPads. Apple fixed it in iOS/iPadOS 14.8.1 and 15.1. Because CISA lists it as known exploited, unresolved legacy devices should be treated as priority risk.
Executive priority
Treat as high priority for any remaining legacy Apple mobile fleet. Known exploitation and kernel-level impact justify rapid verification, patching, and exception tracking, especially for executives, administrators, and other high-value users.
Technical view
CVE-2021-30900 is a CWE-787 out-of-bounds write in iOS and iPadOS, addressed with improved bounds checking. The reported impact is arbitrary code execution with kernel privileges by a malicious application. CVSS 3.1 is 7.8 with local attack vector, low complexity, no privileges, and user interaction required.
Likely exposure
Exposure is most likely on iPhones and iPads running iOS or iPadOS versions older than 14.8.1 or 15.1. The source bundle does not identify exact vulnerable version ranges beyond Apple’s fixed releases.
Exploitation context
CISA KEV status supports known exploitation. The public bundle does not provide attacker identity, campaign details, exploit maturity, or indicators. The stated route is a malicious application that may execute code with kernel privileges after user interaction.
Researcher notes
The bundle confirms Apple iOS/iPadOS impact, CWE-787, kernel privilege code execution, and fixed versions. It does not include root cause detail, proof-of-concept material, exact vulnerable ranges, or campaign indicators. Avoid inferring exposure beyond unsupported or unpatched affected devices.
Mitigation direction
- Update iPhones and iPads to iOS/iPadOS 14.8.1, 15.1, or later supported releases.
- Prioritize devices that cannot receive current Apple security updates for replacement or isolation.
- Restrict installation of untrusted applications on legacy or unmanaged devices.
- Check Apple and CISA guidance for any newer device-specific instructions.
Validation and detection
- Inventory iOS and iPadOS devices and record OS versions.
- Flag devices below iOS/iPadOS 14.8.1 or 15.1 as potentially exposed.
- Confirm patch status through MDM, device management, or direct device settings.
- Review mobile telemetry for suspicious or unauthorized application installations.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-787: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-30900 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.8 (3.1)
- Known Exploited
- Yes
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CISA KEV status
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H1.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.8HighVector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://support.apple.com/kb/HT212872CVE reference · x_refsource_CONFIRM
- https://support.apple.com/en-us/HT212867CVE reference · x_refsource_MISC
- https://support.apple.com/en-us/HT212868CVE reference · x_refsource_MISC
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-30900CVE reference · government-resource
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Out-of-bounds Write
Out-of-bounds Write represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.