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PatchSiren cyber security CVE debrief

CVE-2016-4656 Apple CVE debrief

CVE-2016-4656 is an Apple iOS memory corruption vulnerability that CISA has listed in its Known Exploited Vulnerabilities (KEV) catalog. That KEV status means CISA has determined the flaw has been exploited in the wild, so defenders should treat remediation as a priority rather than a routine update item. The supplied official records do not provide deeper technical detail, so the safest response is to apply Apple’s guidance, confirm affected devices are updated, and verify remediation across managed fleets.

Vendor
Apple
Product
iOS
CVSS
Unknown
CISA KEV
Listed
Original CVE published
2022-05-24
Original CVE updated
2022-05-24
Advisory published
2022-05-24
Advisory updated
2022-05-24

Who should care

Organizations that use Apple iOS devices, especially security teams, mobile device management administrators, IT operations, and incident responders responsible for keeping iPhone and iPad fleets patched and compliant.

Technical summary

The official corpus identifies the issue only as an Apple iOS memory corruption vulnerability. CISA’s KEV catalog entry indicates known exploitation, but the supplied official records do not include exploit mechanics, affected components, or attack prerequisites. Because it is a memory corruption issue on a widely deployed mobile platform, remediation should be treated as high priority.

Defensive priority

High. CISA KEV inclusion signals known exploitation, and the catalog’s required action is to apply updates per vendor instructions. The supplied timeline also includes a KEV due date of 2022-06-14, which reinforces the urgency of validating patch status on affected iOS devices.

Recommended defensive actions

  • Apply Apple updates according to vendor instructions as soon as possible.
  • Inventory iOS devices and identify which are on vulnerable or unsupported versions.
  • Use MDM or endpoint management to verify patch compliance across the fleet.
  • Prioritize internet-exposed, high-value, and user-owned devices that access sensitive data.
  • Check for signs of compromise or unexpected behavior on devices that could have been exposed before remediation.
  • Track the CISA KEV catalog and NVD record for any updated guidance or clarifications.

Evidence notes

This debrief is based only on the supplied official corpus: the CISA KEV source item, the CVE record reference, and the NVD detail link. The corpus confirms the vulnerability name, Apple iOS as the product, and KEV status with a due date, but it does not provide exploit details, affected versions, or a CVSS score.

Official resources

Public debrief derived from official vulnerability records only. No exploit instructions, reproduction steps, or unsupported technical claims are included.