CVE-2021-1871

Status: AnalyzedCritical (9.8)⚠ Active exploitation

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..

CVSS

Version: 3.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Base score: 9.8

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days: 7.00%
Percentile among all scored CVEs: 94
Score date: 10/7/2026

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

CISA KEV — actively exploited

Added to catalog: 11/3/2021
Remediation due date: 11/17/2021
Known ransomware use: Unknown

🎯 ATT&CK techniques

How this vulnerability is exploited and what the attacker gains, in MITRE ATT&CK terms.

ExploitationT1190 Exploit Public-Facing Applicationinitial access85 %
Primary impactT1059 Command and Scripting Interpreterexecution90 %
Secondary impactT1565.001 Stored Data Manipulationimpact70 %

AV:N sin autenticación permite ejecución remota de código arbitrario (T1190). El arreglo de lógica en navegador/aplicación afecta confidencialidad, integridad y disponibilidad (C:H, I:H, A:H).

Inferred by our analysis agent from the official description, CVSS vector and CWE, and checked by a supervisor. May contain errors.

🛡️ ATT&CK mitigations that cover these techniques

Privileged Account Management Vulnerability Scanning Restrict Web-Based Content Restrict File and Directory Permissions Remote Data Storage Network Segmentation

Affected technologies (6)

Apple — Ipados Apple — Iphone OS Apple — MAC OS X Apple — Macos Debian — Debian Linux Fedoraproject — Fedora

CWEs

NVD-CWE-noinfo

References

Raw JSON (NVD)

Show

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