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CVE-2021-1871

Exploited in the wild. In CISA KEV since 2021‑11‑03. Fixed versions are out.

CVSS 3.19.8CriticalEPSS percentile94th7.0% chance in 30 daysCISA KEVListedsince 2021-11-03, due 2021-11-17
No public exploit knownFix5 products2 fixed builds listed below

Published Updated Sources: CVE.org, NVD, BDU

NVD CVE.org

What to do

Find your product and version, then upgrade to the build on the right.

  • Apple macOSAffected: ≥ unspecified, < 11.2Upgrade to: 11.2Stated by: CVE record
  • Apple iOS and iPadOSAffected: ≥ unspecified, < 14.4Upgrade to: 14.4Stated by: CVE record
  • Apple IpadosAffected: < 14.4Upgrade to: 14.4Stated by: NVD
  • Red Hat Inc. Red Hat Enterprise LinuxAffected: 8Upgrade to: not statedStated by: BDU
  • Fedora Project FedoraAffected: 33Upgrade to: not statedStated by: BDU

Versions as the sources state them. 2 more products have version data. Full version matrix after sign-in

Check it yourselfA free OpenVAS check exists for this CVE. Run it against your hosts.Is your organisation exposed?Request an assessment to establish which checks fit your systems.

Coverage timeline

0 publishers

  1. Added to CISA KEV catalog

    ·CISA KEV

Sourced from public security reporting — each date is when it was published, not when it happened.

What it is

From the CVE record

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..

In plain language

No plain-language summary for this CVE yet.

Exploitation

Where each signal puts this CVE on the scale from published to confirmed exploited.

EPSS94th
CISA KEV
CISA KEV

Listed as exploited in the wild since 2021-11-03.

US federal agencies must remediate by 2021-11-17.

Apply updates per vendor instructions.
Public exploits

No public exploit or proof of concept found in the sources we track.

EPSS

7.0% chance of exploitation activity in the next 30 days, which ranks it in the 94th percentile of scored CVEs.

Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.

Lifecycle

6 events over 1910 days, from the signal feeds we watch.

  1. OpenVAS check added
  2. Patch availablerecord updated
  3. Added to CISA KEV
  4. Publishedweakness classified

Affected products

And 7 more affected products. See all after sign-in

Technical detail

CVSS 3.1 vector

Open in the CVSS calculator

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Scored 9.8 by NVD.

How it is reached

  • Attack Vector NetworkExploitable remotely over the network without any special conditions
  • Attack Complexity LowNo special conditions — the attack can be reliably reproduced
  • Privileges Required NoneNo authentication required — anyone can exploit this
  • User Interaction NoneNo user interaction needed — fully automated exploitation

Scope

  • Scope UnchangedImpact is limited to the vulnerable component itself

Impact if exploited

  • Confidentiality HighTotal information disclosure — all data in the component is compromised
  • Integrity HighTotal loss of integrity — attacker can modify any data in the component
  • Availability HighTotal denial of service — the component is completely unavailable

Weaknesses

Sources

References in the record

And 9 more references. See all after sign-in

Watch the software you run.

My Stack ranks new CVEs for your products by real-world exploitation, so the next exploited one reaches you without reading every advisory.

We'll flag the next CVE, public exploit or patch for macOS, not every advisory. This one: actively exploited.