CVE-2016-4657
Published: 25 August 2016
Summary
CVE-2016-4657 is a high-severity Out-of-bounds Write (CWE-787) vulnerability in Apple Iphone Os. Its CVSS base score is 8.8 (High).
Operationally, ranked in the top 0.9% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified are NIST 800-53 SI-16 (Memory Protection) and SI-2 (Flaw Remediation).
Deeper analysis
WebKit, the browser rendering engine in Apple iOS versions prior to 9.3.5, contains a memory corruption vulnerability tracked as CVE-2016-4657 and assigned CWE-787. The flaw is reachable remotely and carries a CVSS 3.1 base score of 8.8, reflecting network attack vector, low complexity, no required privileges, and required user interaction, with high impact on confidentiality, integrity, and availability.
An unauthenticated remote attacker can exploit the issue by serving a specially crafted web page that triggers out-of-bounds memory access when rendered in Safari or any WebKit-based application. Successful exploitation permits arbitrary code execution in the context of the mobile Safari process or, alternatively, a denial-of-service crash.
Apple’s security advisory and the corresponding support document HT207107 state that the vulnerability is resolved in iOS 9.3.5; users are advised to install the update promptly. Public references also link the same WebKit flaw to the Trident exploit kit observed in targeted mobile surveillance campaigns.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2016-5643
Vulnerability details
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.
- CWE(s)
- KEV Date Added
- 24 May 2022
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly requires timely application of the iOS 9.3.5 update that patches the WebKit memory-corruption flaw before exploitation.
Implements memory-protection safeguards that block out-of-bounds writes and subsequent arbitrary code execution in the WebKit process.
Deploys malicious-code detection and blocking mechanisms that can intercept or alert on crafted web content targeting the WebKit vulnerability.