Security Resilience

CVE-2021-30762

Memory Safety in Apple Iphone Os ≤ 12.5.4

CISA KEVActive ExploitationEUVD ExploitedMemory Safety
Published
08 September 2021
Modified
23 October 2025
KEV Added
03 November 2021
Patch / advisory
CVSS Score v3.1 8.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.11 96th percentile
Risk Priority 90 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2021-30762 is a high-severity Use After Free (CWE-416) vulnerability in Apple Iphone Os. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique OS Credential Dumping (T1003); ranked in the top 4% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog.

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 use-after-free vulnerability, tracked as CVE-2021-30762 and assigned CWE-416, affects iOS prior to version 12.5.4. The flaw resides in the handling of web content and was resolved through improved memory management. Successful exploitation can result in arbitrary code execution, as reflected in its CVSS 3.1 score of 8.8.

An unauthenticated remote attacker can trigger the issue by supplying maliciously crafted web content that a user visits or renders, requiring no privileges and only user interaction to achieve full compromise of the affected device.

Apple's advisory HT212548 states that the vulnerability is fixed in iOS 12.5.4, and CISA includes the CVE in its catalog of known exploited vulnerabilities, confirming the availability of the patch as the primary mitigation.

Apple has reported that the issue may have been actively exploited in the wild.

EU & UK References

Vulnerability Data

A use after free issue was addressed with improved memory management. This issue is fixed in iOS 12.5.4. Processing maliciously crafted web content may lead to arbitrary code execution. Apple is aware of a report that this issue may have…

more

been actively exploited..

CWE(s)
KEV Date Added
03 November 2021

Related Threats

MITRE ATT&CK Enterprise Techniques

T1003 OS Credential Dumping Credential Access
Adversaries may attempt to dump credentials to obtain account login and credential material, normally in the form of a hash or a clear text password.
T1003.001 LSASS Memory Credential Access
Adversaries may attempt to access credential material stored in the process memory of the Local Security Authority Subsystem Service (LSASS).
T1003.004 LSA Secrets Credential Access
Adversaries with SYSTEM access to a host may attempt to access Local Security Authority (LSA) secrets, which can contain a variety of different credential materials, such as credentials for service accounts.
T1007 System Service Discovery Discovery
Adversaries may try to gather information about registered local system services.
T1008 Fallback Channels Command And Control
Adversaries may use fallback or alternate communication channels if the primary channel is compromised or inaccessible in order to maintain reliable command and control and to avoid data transfer thresholds.
T1011 Exfiltration Over Other Network Medium Exfiltration
Adversaries may attempt to exfiltrate data over a different network medium than the command and control channel.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-41974Same product: Apple Iphone Osboth on KEV
CVE-2023-43000Same product: Apple Iphone Osboth on KEV
CVE-2023-28205Same product: Apple Iphone Osboth on KEV
CVE-2019-8605Same product: Apple Iphone Osboth on KEV
CVE-2022-22620Same product: Apple Iphone Osboth on KEV
CVE-2025-24085Same product: Apple Iphone Osboth on KEV
CVE-2021-30661Same product: Apple Iphone Osboth on KEV
CVE-2025-43529Same product: Apple Iphone Osboth on KEV
CVE-2025-43511Same product: Apple Iphone Os
CVE-2019-8526Same vendor: Appleboth on KEV

Affected Assets

apple
iphone os
≤ 12.5.4

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 3 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V1.4.3

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.

addresses: CWE-416

Use-after-free exploits that achieve arbitrary code execution are blocked or significantly hardened by non-executable pages and ASLR.

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.

ID.RA-01 partial match
blocks

Vulnerability identification processes can discover use-after-free issues via scanning or analysis but do not prevent their introduction.

PR.PS-02 partial match
blocks

Routine patching removes known use-after-free instances after they have been introduced in released software.

PR.PS-06 partial match
blocks

Secure SDLC practices directly incorporate memory-safety tooling and reviews that prevent most use-after-free defects.

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.

removes
removes
removes
removes

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (higher-evidence rows only; rows rated `none` are excluded).

Oracle Linux 8 (1 rule)
  • V-248592 OL 8 must clear memory when it is freed to prevent use-after-free attacks. blocks CWE-416
RHEL 8 (1 rule)
  • V-230279 RHEL 8 must clear memory when it is freed to prevent use-after-free attacks. blocks CWE-416
RHEL 9 (1 rule)
  • V-257794 RHEL 9 must clear memory when it is freed to prevent use-after-free attacks. blocks CWE-416

References