Apple watchOS up to 9.3.1 FontParser memory corruption

CVSS Meta Temp Score
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CTI Interest Score
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5.0$0-$5k0.00

Summaryinfo

A vulnerability, which was classified as problematic, was found in Apple watchOS up to 9.3.1. This affects an unknown part of the component FontParser. Executing a manipulation can lead to memory corruption. This vulnerability is registered as CVE-2023-27956. It is possible to launch the attack remotely. No exploit is available. You should upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic was found in Apple watchOS up to 9.3.1 (Smartwatch Operating System). This vulnerability affects some unknown functionality of the component FontParser. The manipulation with an unknown input leads to a memory corruption vulnerability. The CWE definition for the vulnerability is CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. As an impact it is known to affect confidentiality. CVE summarizes:

The issue was addressed with improved memory handling. This issue is fixed in macOS Ventura 13.3, iOS 16.4 and iPadOS 16.4, iOS 15.7.4 and iPadOS 15.7.4, tvOS 16.4, watchOS 9.4. Processing a maliciously crafted image may result in disclosure of process memory.

The weakness was published 03/27/2023 by Ye Zhang as HT213678 as confirmed advisory (Website). The advisory is shared for download at support.apple.com. This vulnerability was named CVE-2023-27956. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. The advisory points out:

Processing a maliciously crafted image may result in disclosure of process memory

Upgrading to version 9.4 eliminates this vulnerability. A possible mitigation has been published immediately after the disclosure of the vulnerability. The advisory contains the following remark:

The issue was addressed with improved memory handling.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2023-31682). Once again VulDB remains the best source for vulnerability data.

Productinfo

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Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.1
VulDB Meta Temp Score: 5.0

VulDB Base Score: 4.3
VulDB Temp Score: 4.1
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔍

CNA Base Score: 5.5
CNA Vector: 🔍

CVSSv2info

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

Exploitinginfo

Class: Memory corruption
CWE: CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Yes

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: watchOS 9.4

Timelineinfo

03/08/2023 🔍
03/27/2023 +18 days 🔍
03/27/2023 +0 days 🔍
03/29/2023 +2 days 🔍
11/30/2025 +977 days 🔍

Sourcesinfo

Vendor: apple.com

Advisory: HT213678
Researcher: Ye Zhang
Status: Confirmed

CVE: CVE-2023-27956 (🔍)
GCVE (CVE): GCVE-0-2023-27956
GCVE (VulDB): GCVE-100-224380
EUVD: 🔍

Entryinfo

Created: 03/29/2023 14:46
Updated: 11/30/2025 05:05
Changes: 03/29/2023 14:46 (19), 03/29/2023 14:50 (27), 04/19/2023 09:16 (1), 12/12/2024 16:40 (27), 01/29/2025 17:14 (11), 04/27/2025 15:08 (3), 11/30/2025 05:05 (1)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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