Threats / Apple / CVE-2016-4657
CVE-2016-4657
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
Apple iOS vulnerability
Apple iOS WebKit memory corruption vulnerability enabling remote code execution or denial-of-service through malicious web content.
Verdict
Today item — known-exploited.
Memory safety defect in WebKit HTML parsing allows unauthenticated remote attackers to achieve code execution on iOS devices via crafted websites. Exploitation observed in the wild. High severity due to ubiquitous browser exposure.
01
Is it exploitable?
— the evidence, ranked above the scoreExploit available
Public proof-of-concept exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
6 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-05-24).
Probability (EPSS)
EPSS 0.66788 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Apple, iOS. Confirm exact fixed builds in the vendor advisory.
Weakness (CWE)
Mapped to CWE-119 Memory Buffer Bounds Error — weakness family: Memory safety.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
Craft a malicious webpage containing specially formatted HTML to trigger memory corruption in WebKit's parser.
Business
iOS users exposed to arbitrary code execution risk when visiting untrusted websites or clicking malicious links.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
Deliver the malicious webpage through compromised sites, phishing campaigns, or watering hole attacks targeting iOS users.
Business
Apple's security reputation damaged by widespread exploitation; user trust in Safari and iOS security eroded.
3
Lateral reach — past segmentation narrative 3
Attacker
Execute arbitrary code with the privileges of the Safari process to exfiltrate data, install malware, or pivot to system compromise.
Business
Customer data breaches, device compromise, and potential lateral movement to corporate networks via infected personal devices.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05