CVE-2021-30761
Apple iOS WebKit Memory Corruption Vulnerability - [Actively Exploited]
Description
A memory corruption issue was addressed with improved state 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 been actively exploited..
INFO
Published Date :
Sept. 8, 2021, 2:15 p.m.
Last Modified :
Oct. 23, 2025, 6:04 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CISA KEV (Known Exploited Vulnerabilities)
For the benefit of the cybersecurity community and network defenders—and to help every organization better manage vulnerabilities and keep pace with threat activity—CISA maintains the authoritative source of vulnerabilities that have been exploited in the wild.
Apple iOS WebKit contains a memory corruption vulnerability that leads to code execution when processing maliciously crafted web content. This vulnerability could impact HTML parsers that use WebKit, including but not limited to Apple Safari and non-Apple products which rely on WebKit for HTML processing.
Apply updates per vendor instructions.
https://nvd.nist.gov/vuln/detail/CVE-2021-30761
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 2.0 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 3.1 | HIGH | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
Solution
- Upgrade to iOS version 12.5.4 or later.
- Update the affected packages.
Public PoC/Exploit Available at Github
CVE-2021-30761 has a 2 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2021-30761.
| URL | Resource |
|---|---|
| https://support.apple.com/en-us/HT212548 | Release Notes Vendor Advisory |
| https://support.apple.com/en-us/HT212548 | Release Notes Vendor Advisory |
| https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-30761 | Third Party Advisory US Government Resource |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-30761 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2021-30761
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
None
Python Dockerfile
Ostorlab KEV: One-command to detect most remotely known exploitable vulnerabilities. Sourced from CISA KEV, Google's Tsunami, Ostorlab's Asteroid and Bug Bounty programs.
cisa-kev vulnerability 0day cisa exploits
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2021-30761 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2021-30761 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Modified Analysis by [email protected]
Oct. 23, 2025
Action Type Old Value New Value Added Reference Type CISA-ADP: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-30761 Types: Third Party Advisory, US Government Resource -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Oct. 22, 2025
Action Type Old Value New Value Added Reference https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-30761 -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Oct. 21, 2025
Action Type Old Value New Value Removed Reference https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-30761 -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Oct. 21, 2025
Action Type Old Value New Value Added Reference https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-30761 -
Modified Analysis by [email protected]
Feb. 13, 2025
Action Type Old Value New Value -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jan. 29, 2025
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Added CWE CWE-787 -
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Nov. 21, 2024
Action Type Old Value New Value Added Reference https://support.apple.com/en-us/HT212548 -
CVE CISA KEV Update by 9119a7d8-5eab-497f-8521-727c672e3725
May. 16, 2024
Action Type Old Value New Value Changed Vulnerability Name Apple iOS Memory Corruption Vulnerability Apple iOS WebKit Memory Corruption Vulnerability -
CVE Modified by [email protected]
May. 14, 2024
Action Type Old Value New Value -
Initial Analysis by [email protected]
Sep. 14, 2021
Action Type Old Value New Value Added CVSS V2 Metadata Victim must voluntarily interact with attack mechanism Added CVSS V2 NIST (AV:N/AC:M/Au:N/C:P/I:P/A:P) Added CVSS V3.1 NIST AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Changed Reference Type https://support.apple.com/en-us/HT212548 No Types Assigned https://support.apple.com/en-us/HT212548 Release Notes, Vendor Advisory Added CWE NIST CWE-787 Added CPE Configuration OR *cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:* versions up to (excluding) 12.5.4
Vulnerability Scoring Details
Base CVSS Score: 8.8
Base CVSS Score: 6.8
Exploit Prediction
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.
0.51 }} -0.22%
score
0.65532
percentile