Exploited vulnerability · CISA KEV

Is CVE-2016-4657 exploited? Yes: in CISA KEV since 24 May 2022

Gociux · Apple iOS · data: CISA KEV, CVE record, FIRST EPSS

Yes. CVE-2016-4657, Apple iOS Webkit Memory Corruption Vulnerability, is being exploited in the wild. CISA added it to its Known Exploited Vulnerabilities catalog on 24 May 2022, 2098 days after it was published. It affects Apple iOS. If you run it, CISA's required action is: Apply updates per vendor instructions.

exploitedYesCISA KEV · 24 May 2022

ransomwareNot knownno confirmed use

EPSStop 1%among the most likely CVEs to be exploited

severity8.8CVSS 3.1 · high

US federal due14 Jun 2022BOD 22-01 deadline

What it is

Apple iOS WebKit contains a memory corruption vulnerability that allows attackers to execute remote code or cause a denial-of-service (DoS) via a crafted web site. This vulnerability could impact HTML parsers that use WebKit, including but not limited to Apple Safari and non-Apple products which rely on WebKit for HTML processing.

Vendor	Apple (96 exploited CVEs in KEV)
Product	iOS
Vulnerability	Apple iOS Webkit Memory Corruption Vulnerability
Weakness	CWE-119
Published	25 Aug 2016
Added to KEV	24 May 2022
Reported by (CNA)	apple

What to do

Check whether you run it. Look for iOS in your asset inventory, including appliances and cloud images. Stack check lists every exploited Apple CVE at once.
Apply the fix. Apply updates per vendor instructions.
If you can't patch today, take the affected service off the internet or restrict who can reach it, and check its logs for signs of compromise since 25 Aug 2016.
Get told next time. Email alerts when CISA adds a CVE for Apple.

Other exploited CVEs in iOS

CVE-2022-42856: Apple iOS Type Confusion Vulnerability (14 Dec 2022)
CVE-2016-4655: Apple iOS Information Disclosure Vulnerability (24 May 2022)
CVE-2016-4656: Apple iOS Memory Corruption Vulnerability (24 May 2022)
CVE-2019-7287: Apple iOS Memory Corruption Vulnerability (23 May 2022)
CVE-2021-30762: Apple iOS WebKit Use-After-Free Vulnerability (3 Nov 2021)
CVE-2021-30666: Apple iOS WebKit Buffer Overflow Vulnerability (3 Nov 2021)

References

nvd.nist.gov/vuln/detail/CVE-2016-4657

Questions

Is CVE-2016-4657 being exploited?

Yes. CISA added CVE-2016-4657 to the Known Exploited Vulnerabilities catalog on 24 May 2022, which means there is reliable evidence of exploitation in the wild.

Is CVE-2016-4657 used in ransomware attacks?

CISA does not list known ransomware use for it. That can change, and exploitation alone is reason to fix it first.

How do I fix CVE-2016-4657?

Apply updates per vendor instructions. Check Apple's advisory for the fixed versions, and if you can't patch quickly, restrict access to the affected iOS and watch it for signs of compromise.

Sources: CISA KEV (exploitation, ransomware use, required action, due date), the CVE record (publication date, CVSS, CNA), NVD and FIRST EPSS (live score). More: all KEV additions in May 2022 · Apple scorecard · act-now radar.

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