Your RSA-2048 keys break in 2030. Find every one of them before attackers do.
🛡️
CISA KEV · ACTIVELY EXPLOITED
HIGH severity

CVE-2021-30883

HIGH

CVE-2021-30883 is a high-severity (CVSS 7.8) Out-of-bounds Write vulnerability in apple ipados. It is in CISA's Known Exploited Vulnerabilities catalog (added 2022-05-23) — treat it as actively exploited and patch now. O3 Security detects and blocks CVE-2021-30883 exploitation at runtime via eBPF exploit-chain detection and L7 egress monitoring, even on unpatched systems.

A memory corruption issue was addressed with improved memory handling. This issue is fixed in iOS 15.0.2 and iPadOS 15.0.2, macOS Monterey 12.0.1, iOS 14.8.1 and iPadOS 14.8.1, tvOS…

Published
Aug 24, 2021
Updated
Jun 17, 2026
Affected
5 products
Patched
See advisory
Exploits
3 known
Exploitation data as of Aug 27, 2026 · OSV.dev, NVD, CISA KEV, FIRST.org (EPSS)

Exploitation Status

Actively exploited in the wild

  • Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2022-05-23. Federal agencies were required to remediate by 2022-06-13.
  • A successful exploit gives an attacker total control of the affected component, not partial access.

Exploitation and automatability from CISA (KEV catalog and SSVC triage) for CVE-2021-30883.

EPSS Exploitation Probability

via FIRST.org ↗
14.7%probability of exploitation in next 30 days
Moderate Risk0.00%
Lower risk than most CVEs96th percentile — riskier than 96% of all scored CVEsHighest risk
0.00%6.34%12.7%19.0%0.6%0.4%14.7%14.7%Mar 26Jul 26Aug 26

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

How urgent is this, really

CVE-2021-30883 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.

Where this sits among everything scored

Of 0 CVEs with a current EPSS score, this one falls in the 10–50% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.

Description

A memory corruption issue was addressed with improved memory handling. This issue is fixed in iOS 15.0.2 and iPadOS 15.0.2, macOS Monterey 12.0.1, iOS 14.8.1 and iPadOS 14.8.1, tvOS 15.1, watchOS 8.1, macOS Big Sur 11.6.1. An application may be able to execute arbitrary code with kernel privileges. Apple is aware of a report that this issue may have been actively exploited..

Affected Products

5 products · 8 configurations
OS
ipadosapple
≥ 15.0 && < 15.0.2
range
OS
iphone osapple
≥ 15.0 && < 15.0.2
range
OS
macosapple
≥ 11.0 && < 11.6.1
1 version
12.0
OS
tvosapple
< 15.1
range
OS
watchosapple
< 8.1
range
Exploits & PoCs
3

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

Detection & mitigation playbook

Vendor / appliance
  1. Detect

    Inventory every apple ipados deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for remote code execution at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.

  2. Fix

    Apply the apple ipados security patch or hotfix for CVE-2021-30883 on the affected version, following the vendor advisory for your exact build.

  3. Workarounds

    Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.

  4. How O3 protects you

    O3 detects and blocks CVE-2021-30883 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.

Tailored to CVE-2021-30883. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

A memory corruption issue was addressed with improved memory handling. This issue is fixed in iOS 15.0.2 and iPadOS 15.0.2, macOS Monterey 12.0.1, iOS 14.8.1 and iPadOS 14.8.1, tvOS 15.1, watchOS 8.1, macOS Big Sur 11.6.1. An application may be able to execute arbitrary code with kernel privileges. Apple is aware of a report that this issue may have been actively exploited..
O3 Security · Runtime Protection

Is CVE-2021-30883 being exploited in your environment?

O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2021-30883 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.

CVE-2021-30883: IPADOS Out-of-bounds… | O3 Security