# CVE-2016-4657: Apple iOS Webkit Memory Corruption Vulnerability

Source: https://junglewise.ai/threats/cve-2016-4657-apple-ios-webkit-memory-corruption-vulnerability  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2022-05-24. Updated: 2026-05-10  
License: CC BY 4.0 with a link back

CVE-2016-4657 · Severity: critical · CVSS 8.8 · Exploited in the wild · Published 2022-05-24

WebKit in Apple iOS contains a memory corruption vulnerability (out-of-bounds write) that allows remote attackers to execute arbitrary code or cause a denial of service via a crafted website. This vulnerability was famously exploited as part of the 'Trident' exploit chain used by the Pegasus spyware.

Technologies: [Apple iPadOS](https://junglewise.ai/threats/technologies/ipados), [Apple macOS](https://junglewise.ai/threats/technologies/macos), [Apple watchOS](https://junglewise.ai/threats/technologies/watchos), [Cisco IOS](https://junglewise.ai/threats/technologies/ios). Vendors: [Apple](https://junglewise.ai/threats/vendors/apple), [Cisco](https://junglewise.ai/threats/vendors/cisco).

## Quick answers

**Is CVE-2016-4657 exploited in the wild?** Yes. CVE-2016-4657 is known to be exploited in the wild, first recorded on 24 May 2022. Treat it as urgent.

**How severe is CVE-2016-4657?** Critical severity, with a CVSS score of 8.8, published 24 May 2022.

**Which products and versions are affected?** Apple iOS before 9.3.5; Apple WebKit before 9.3.5.

**Is there a fix for CVE-2016-4657?** A patch was published on 2016-08-25: Apple released iOS 9.3.5 to address the vulnerability. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2016-4657 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2016-4657?** Check whether you run Apple iPadOS, Apple macOS, Apple watchOS or one of the others listed. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Affected products

- Apple iOS before 9.3.5
- Apple WebKit before 9.3.5

## Timeline

- 2016-08-25: disclosed: Public disclosure of Trident/Pegasus exploit chain.
- 2016-08-25: patched: Apple released iOS 9.3.5 to address the vulnerability.
- 2022-05-24: kev added: Added to CISA Known Exploited Vulnerabilities Catalog.
- 2016-08-25: exploited: Reported as exploited in the wild by Lookout/Citizen Lab.

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