Is CVE-2021-1879 actively exploited?

Yes. CVE-2021-1879 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, which means exploitation in the wild has been confirmed.

Can CVE-2021-1879 be exploited remotely?

The attack vector of CVE-2021-1879 has not been classified yet.

What is the CVSS score of CVE-2021-1879?

CVE-2021-1879 has not received a CVSS score yet.

HOME VULNERABILITIESCVE-2021-1879

HIGHCISA KEVIN THE WILD

CVE-2021-1879

Published: November 3, 2021

EPSS:1.50%probability of exploitation in 30 daysPercentile:80.9th

Official Description

Apple iOS, iPadOS, and watchOS WebKit contain an unspecified vulnerability that allows for universal cross-site scripting (XSS) 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.

NVD Source

CISA KEV Advisory

Apple iOS, iPadOS, and watchOS WebKit Cross-Site Scripting (XSS) Vulnerability

Added to KEV: 2021-11-03Federal patch deadline: 2021-11-17

Required Action (CISA)

Apply updates per vendor instructions.

Risk Analysis

This high-severity unspecified vulnerability in Apple iOS, iPadOS, and watchOS WebKit allows for universal cross-site scripting (XSS) when processing maliciously crafted web content. Its inclusion in CISA's KEV catalog and an EPSS score of 0.01503 indicate confirmed exploitation and a notable likelihood of future exploitation, affecting Apple Safari and other WebKit-reliant products.

This vulnerability is actively being exploited in the wild, confirming its use by attackers. Exploitation occurs when processing maliciously crafted web content.

Recommended Action

Apply the latest security updates for Apple iOS, iPadOS, and watchOS. Exercise caution when visiting untrusted websites and ensure all web browsers are kept up to date.

Generated by the CTIWATCH analysis pipeline from this CVE's metadata (CVSS, EPSS, KEV status, exploit intelligence). Verify against vendor advisories before acting.

Technical Analysis

CVE-2021-1879 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

CISA has added CVE-2021-1879 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.