# CVE-2016-4657 — Apple Iphone Os

**CISA KEV**

> As of 2025-10-21, CVE-2016-4657 is a HIGH-severity vulnerability in Apple Iphone Os, CVSS v3.1 8.8, EPSS 63.5% (99.1th percentile). It is listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-05-24), with a US federal remediation deadline of 2022-06-14. Threadlinqs Intelligence links 2 tracked threat campaigns to CVE-2016-4657, most recently “NSO Group Co-Founder Shalev Hulio Held Israeli Diplomatic Passport in Panama, Raising State-Ties Questions for Pegasus Spyware Vendor”.

**Last updated:** 2025-10-21

## What is CVE-2016-4657?

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.

The record classifies CVE-2016-4657 under weakness class [CWE-787](https://cwe.mitre.org/data/definitions/787.html). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs a user to take an action first, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 3671 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 8.8 — HIGH (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`)
- **EPSS (FIRST):** 63.5% probability of exploitation in the next 30 days, higher than 99.1% of all scored CVEs
- **CISA KEV:** Listed since 2022-05-24, federal remediation deadline 2022-06-14
- **Threadlinqs priority:** 9/10 — CISA KEV-listed, which Threadlinqs floors at 9
- **Published:** 2016-08-25, last modified 2025-10-21

## Is CVE-2016-4657 being exploited?

CISA added CVE-2016-4657 to the Known Exploited Vulnerabilities catalog on 2022-05-24, which means the agency holds evidence of exploitation in the wild; US federal civilian agencies had to remediate it by 2022-06-14 under BOD 22-01. Weaponised exploit code for CVE-2016-4657 is publicly available. 4 public proof-of-concept repositories are tracked for this identifier. It currently carries a trending score of 43 in the Threadlinqs vulnerability feed.

- [iDaN5x/Switcheroo](https://github.com/iDaN5x/Switcheroo) (github)
- [viai957/webkit-vulnerability](https://github.com/viai957/webkit-vulnerability) (github)
- [Mimoja/CVE-2016-4657-NintendoSwitch](https://github.com/Mimoja/CVE-2016-4657-NintendoSwitch) (github)
- [trickest/cve](https://github.com/trickest/cve/blob/main/2016/CVE-2016-4657.md) (trickest)

## Affected products and versions

- **Apple**: Iphone Os

## How to fix CVE-2016-4657

Vendor advisory: [http://lists.apple.com/archives/security-announce/2016/Aug/msg00000.html](http://lists.apple.com/archives/security-announce/2016/Aug/msg00000.html). Because CVE-2016-4657 is KEV-listed, US federal civilian agencies were required to apply the vendor fix, or stop using the product, by 2022-06-14. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.

## Threat activity tracking CVE-2016-4657

2 tracked threats in the Threadlinqs corpus reference CVE-2016-4657, either in the campaign’s CVE list or as an indicator on the campaign record.

- [NSO Group Co-Founder Shalev Hulio Held Israeli Diplomatic Passport in Panama, Raising State-Ties Questions for Pegasus Spyware Vendor](https://intel.threadlinqs.com/threat/TL-2026-1748) — INFORMATIONAL · 2026-07-28
- [Pegasus Mercenary Spyware Used for State Surveillance of Azerbaijani Journalists, Activists, and Human Rights Defenders (NSO Group)](https://intel.threadlinqs.com/threat/TL-2026-0751) — HIGH · 2026-06-10

## Sources

Enriched from CVE.org, NVD, FIRST EPSS, CISA KEV, public proof-of-concept repositories. Last verified by Threadlinqs on 2026-08-03. This product uses the NVD API but is not endorsed or certified by the NVD.

**Vendor advisory and patch**

- [support.apple.com](https://support.apple.com/HT207107)
- [lists.apple.com — vendor advisory](http://lists.apple.com/archives/security-announce/2016/Aug/msg00000.html)

**Exploit and proof of concept**

- [exploit-db.com — exploit](https://www.exploit-db.com/exploits/44836/)

**Vulnerability database entry**

- [securityfocus.com — vdb entry](http://www.securityfocus.com/bid/92653)
- [securitytracker.com — vdb entry](http://www.securitytracker.com/id/1036694)

**Other references**

- [blog.lookout.com](https://blog.lookout.com/blog/2016/08/25/trident-pegasus/)
- [youtube.com](https://www.youtube.com/watch?v=xkdPjbaLngE)

Canonical: https://intel.threadlinqs.com/cve/CVE-2016-4657
Full detection coverage and IOCs for threats exploiting CVE-2016-4657 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp