VDB-168799 · CVE-2021-1871 · HT212146

Apple iOS/iPadOS up to 14.3 WebKit Remote Code Execution

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
8.5	$5k-$25k	0.00

Summaryinfo

A vulnerability, which was classified as critical, has been found in Apple iOS and iPadOS up to 14.3. This issue affects some unknown processing of the component WebKit. This manipulation causes an unknown weakness. The identification of this vulnerability is CVE-2021-1871. It is possible to initiate the attack remotely. Furthermore, there is an exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability has been found in Apple iOS and iPadOS up to 14.3 (Smartphone Operating System) and classified as critical. Affected by this vulnerability is an unknown functionality of the component WebKit. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

A logic issue was addressed with improved restrictions. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, iOS 14.4 and iPadOS 14.4. A remote attacker may be able to cause arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited..

The weakness was shared 01/26/2021 as HT212146 as confirmed advisory (Website). It is possible to read the advisory at support.apple.com. This vulnerability is known as CVE-2021-1871. It demands that the victim is doing some kind of user interaction. Technical details are unknown but a private exploit is available. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 07/29/2025). It is expected to see the exploit prices for this product increasing in the near future. The advisory points out:

A remote attacker may be able to cause arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited.

It is declared as attacked. The vulnerability scanner Nessus provides a plugin with the ID 241427 (RHEL 7 : webkitgtk4 (RHSA-2025:10364)), which helps to determine the existence of the flaw in a target environment. The CISA Known Exploited Vulnerabilities Catalog lists this issue since 11/03/2021 with a due date of 11/17/2021:

Apply updates per vendor instructions.

Upgrading to version 14.4 eliminates this vulnerability. A possible mitigation has been published immediately after the disclosure of the vulnerability. The advisory contains the following remark:

A logic issue was addressed with improved restrictions.

The vulnerability is also documented in the databases at Zero-Day.cz (601), Tenable (241427) and EUVD (EUVD-2021-7335). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

Smartphone Operating System

Vendor

Apple

Name

Version

License

commercial

Website

Vendor: https://www.apple.com/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.6
VulDB Meta Temp Score: 8.5

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

NVD Base Score: 9.8
NVD Vector: 🔍

CNA Base Score: 9.8
CNA Vector: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

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

NVD Base Score: 🔍

Exploitinginfo

Class: Remote Code Execution
CWE: Unknown
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Access: Private
Status: Attacked

EPSS Score: 🔍
EPSS Percentile: 🔍

KEV Added: 🔍
KEV Due: 🔍
KEV Remediation: 🔍
KEV Ransomware: 🔍
KEV Notice: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Nessus ID: 241427
Nessus Name: RHEL 7 : webkitgtk4 (RHSA-2025:10364)

Zero-Day.cz: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

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

Upgrade: iOS/iPadOS 14.4

Timelineinfo

12/08/2020 🔍
01/26/2021 +49 days 🔍
01/26/2021 +0 days 🔍
01/28/2021 +2 days 🔍
07/29/2025 +1643 days 🔍

Sourcesinfo

Vendor: apple.com

Advisory: HT212146
Status: Confirmed

CVE: CVE-2021-1871 (🔍)
GCVE (CVE): GCVE-0-2021-1871
GCVE (VulDB): GCVE-100-168799
EUVD: 🔍
scip Labs: https://www.scip.ch/en/?labs.20150917

Entryinfo

Created: 01/28/2021 06:21
Updated: 07/29/2025 06:02
Changes: 01/28/2021 06:21 (17), 01/28/2021 06:25 (30), 01/28/2021 06:28 (2), 02/20/2021 19:28 (1), 04/20/2024 13:24 (23), 05/15/2024 17:15 (2), 06/30/2024 10:13 (2), 07/26/2024 22:15 (20), 09/11/2024 11:01 (1), 01/30/2025 00:15 (11), 05/04/2025 07:11 (3), 07/10/2025 09:44 (2), 07/29/2025 06:02 (1)
Complete: 🔍
Cache ID: 216::103