CVE-2016-4657 — Apple iOS Webkit Memory Corruption Vulnerability

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.

01What is this vulnerability?

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.

02Affected products

Vendor	Product	Versions
n	a / n/a	n/a

03Active exploitation status

Yes — actively exploited. Added to the CISA KEV catalog on 2022-05-24. Ransomware use: Unknown.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Open the Sigma generator with a pre-filled prompt for this CVE to draft a starting detection in your stack of choice:

Open in Sigma generator →

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2016-08-25T21:00:00.000Z
• Last modified: 2025-10-21T23:55:50.057Z
• Added to CISA KEV: 2022-05-24
• BOD 22-01 due: 2022-06-14

09References

• blog.lookout.com — https://blog.lookout.com/blog/2016/08/25/trident-pegasus/
• www.youtube.com — https://www.youtube.com/watch?v=xkdPjbaLngE
• www.exploit-db.com — https://www.exploit-db.com/exploits/44836/
• www.securityfocus.com — http://www.securityfocus.com/bid/92653
• support.apple.com — https://support.apple.com/HT207107
• lists.apple.com — http://lists.apple.com/archives/security-announce/2016/Aug/msg00000.html
• www.securitytracker.com — http://www.securitytracker.com/id/1036694