Apple watchOS up to 7.5 libxml2 use after free

CVSS Meta Temp Score
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CTI Interest Score
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7.4$0-$5k0.00

Summaryinfo

A vulnerability, which was classified as critical, has been found in Apple watchOS up to 7.5. This impacts an unknown function of the component libxml2. This manipulation causes an unknown weakness. This vulnerability is handled as CVE-2021-3518. The attack can be initiated remotely. There is not any exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical was found in Apple watchOS up to 7.5 (Smartwatch Operating System). Affected by this vulnerability is an unknown functionality of the component libxml2. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. As an impact it is known to affect confidentiality, integrity, and availability.

The weakness was released 07/19/2021 as HT212605 as confirmed advisory (Website). It is possible to read the advisory at support.apple.com. This vulnerability is known as CVE-2021-3518. It demands that the victim is doing some kind of user interaction. The technical details are unknown and an exploit is not publicly available. The advisory points out:

A remote attacker may be able to cause arbitrary code execution

The vulnerability scanner Nessus provides a plugin with the ID 236735 (Alibaba Cloud Linux 3 : 0047: libxml2 (ALINUX3-SA-2021:0047)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 7.6 eliminates this vulnerability. A possible mitigation has been published immediately after the disclosure of the vulnerability. The advisory contains the following remark:

This issue was addressed with improved checks.

The vulnerability is also documented in the vulnerability database at Tenable (236735). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

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Version

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Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.6
VulDB Meta Temp Score: 7.4

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 8.8
NVD Vector: 🔍

CVSSv2info

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

NVD Base Score: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 236735
Nessus Name: Alibaba Cloud Linux 3 : 0047: libxml2 (ALINUX3-SA-2021:0047)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

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

Upgrade: watchOS 7.6

Timelineinfo

04/27/2021 🔍
07/19/2021 +83 days 🔍
07/19/2021 +0 days 🔍
07/23/2021 +4 days 🔍
05/16/2025 +1393 days 🔍

Sourcesinfo

Vendor: apple.com

Advisory: HT212605
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2021-3518 (🔍)
GCVE (CVE): GCVE-0-2021-3518
GCVE (VulDB): GCVE-100-179551

Entryinfo

Created: 07/23/2021 10:02
Updated: 05/16/2025 05:04
Changes: 07/23/2021 10:02 (9), 07/23/2021 10:03 (8), 07/23/2021 10:06 (27), 07/28/2021 09:02 (3), 07/28/2021 09:03 (19), 05/16/2025 05:04 (17)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

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