KEV Intelligence

Vulnerability report

Exploited in the wild Confirmed confidence In CISA KEV

CVE-2016-4657

iOS Denial of Service

Apple / iOS

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Severity
CVSS 8.8 · High
Confidence
Confirmed
Exploit status
Exploited in the wild
EPSS
63.6%
First observed
—
Last observed
—

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2016-4657 is an unauthenticated vulnerability affecting Apple iOS. WebKit in Apple iOS before 9.3.5 allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted...

Is it exploited?

Yes. KEV Intelligence tracks this CVE as a known exploited vulnerability. Confidence is confirmed.

Who is affected?

Apple / iOS.

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

iOS Denial of Service

WebKit in Apple iOS before 9.3.5 allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted web site.

View vendor advisory (opens in new tab)
Published
25 Aug 2016
Exploitation Reported
24 May 2022
Attack vector
Remote
Complexity
Low
Privileges
None
User interaction
Required

Tags

ios metasploit cisa

CVE References

  • CVE Record CVE.org · CVE Record https://www.cve.org/CVERecord?id=CVE-2016-4657
  • APPLE-SA-2016-08-25-1 lists.apple.com · Vendor Advisory http://lists.apple.com/archives/security-announce/2016/Aug/msg00000.html
  • 44836 exploit-db.com · Exploit https://www.exploit-db.com/exploits/44836/
  • 92653 securityfocus.com · VDB Entry http://www.securityfocus.com/bid/92653
  • 1036694 securitytracker.com · VDB Entry http://www.securitytracker.com/id/1036694
  • blog.lookout.com/blog/2016/08/25/trident-pegasus blog.lookout.com · CVE Record https://blog.lookout.com/blog/2016/08/25/trident-pegasus/
  • youtube.com/watch youtube.com · CVE Record https://www.youtube.com/watch?v=xkdPjbaLngE
  • support.apple.com/HT207107 support.apple.com · CVE Record https://support.apple.com/HT207107

Exploitation evidence

Why KEV Intelligence marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

CISA

Recorded 24 May 2022

Independent exploitation attestation added to the KEV Intelligence record.

Proof of concept available

GitHub

Recorded 13 Mar 2017

Public scanner or PoC coverage increases practical exploitability.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the KEV Intelligence Pro API.

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Source Added
CISA First 2022-05-24 00:00 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets
0
User-Agents
0

Raw values available in Pro and Enterprise.

Virtual patch status

No KEV Intelligence virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

Scanner Artifacts

Scanner and exploit-framework references linked to this CVE.

Scanner Reference Detected
Metasploit https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/apple_ios/browser/webkit_trident.rb 28 Apr 2025

Risk and context

Severity, weaknesses, and research context

CVSS v3.1

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

EPSS

63.6%

Weaknesses

Out-of-bounds Write CWE-787

All CVSS Scores

CVSS v3.1 8.8 High

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

CVSS v2.0 6.8 Medium

AV:N/AC:M/Au:N/C:P/I:P/A:P

Potential Proof of Concepts

These PoCs are unverified and could contain malware. Use at your own risk.

webkit_trident

metasploit · Created Unknown

Metasploit module for CVE-2016-4657

Timeline

From disclosure to observed exploitation

  1. Metasploit module available

    Exploit module available

  2. Public PoC available

    Public proof-of-concept code published

  3. Added to CISA KEV

    Listed in the CISA Known Exploited Vulnerabilities catalog

  4. CVE published

    Vulnerability disclosed publicly

  5. CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2016-4657

Free JSON includes basic KEV fields 
{
  "cve_id": "CVE-2016-4657",
  "confidence": "Confirmed",
  "cvss_score": 8.8,
  "cvss_estimated": false,
  "epss_score": 0.63579,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}

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