Apple iOS/iPadOS up to 15.1.1 Kernel race condition

CVSS Meta Temp Score
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CTI Interest Score
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7.5$0-$5k0.00

Summaryinfo

A vulnerability was found in Apple iOS and iPadOS up to 15.1.1. It has been declared as critical. Affected is an unknown function of the component Kernel. Executing a manipulation can lead to race condition. This vulnerability is tracked as CVE-2021-30955. The attack is restricted to local execution. No exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability has been found in Apple iOS and iPadOS up to 15.1.1 (Smartphone Operating System) and classified as critical. This vulnerability affects some unknown processing of the component Kernel. The manipulation with an unknown input leads to a race condition vulnerability. The CWE definition for the vulnerability is CWE-362. The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. As an impact it is known to affect confidentiality, integrity, and availability.

The weakness was disclosed 12/13/2021 by Zweig as HT212976 as confirmed advisory (Website). The advisory is shared for download at support.apple.com. This vulnerability was named CVE-2021-30955. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 03/07/2026). It is expected to see the exploit prices for this product increasing in the near future. The advisory points out:

A malicious application may be able to execute arbitrary code with kernel privileges

Upgrading to version 15.2 eliminates this vulnerability. A possible mitigation has been published immediately after the disclosure of the vulnerability. The advisory contains the following remark:

A race condition was addressed with improved state handling.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-0631). Once again VulDB remains the best source for vulnerability data.

Affected

  • Apple macOS

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.8
VulDB Meta Temp Score: 7.5

VulDB Base Score: 7.8
VulDB Temp Score: 7.5
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Race condition
CWE: CWE-362
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: No

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍

Upgrade: iOS/iPadOS 15.2

Timelineinfo

04/13/2021 🔍
12/13/2021 +244 days 🔍
12/13/2021 +0 days 🔍
12/17/2021 +4 days 🔍
03/07/2026 +1541 days 🔍

Sourcesinfo

Vendor: apple.com

Advisory: HT212976
Researcher: Zweig
Status: Confirmed

CVE: CVE-2021-30955 (🔍)
GCVE (CVE): GCVE-0-2021-30955
GCVE (VulDB): GCVE-100-188572
CERT Bund: WID-SEC-2026-0631 - Apple macOS: Mehrere Schwachstellen

scip Labs: https://www.scip.ch/en/?labs.20150917

Entryinfo

Created: 12/17/2021 16:45
Updated: 03/07/2026 19:32
Changes: 12/17/2021 16:45 (19), 12/17/2021 16:48 (28), 12/23/2021 10:00 (1), 03/07/2026 19:32 (21)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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