CVE-2017-11121

Severity: critical (CVSS 9.8 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 2.8% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2017-09-28 · updated 2026-06-17
Weakness: CWE-119

Description

On Broadcom BCM4355C0 Wi-Fi chips 9.44.78.27.0.1.56 and other chips, properly crafted malicious over-the-air Fast Transition frames can potentially trigger internal Wi-Fi firmware heap and/or stack overflows, leading to denial of service or other effects, aka B-V2017061205.

Affected products

Apple Iphone Os: before 11.0 — fixed in 11.0
Apple tvOS: before 11.0 — fixed in 11.0
Broadcom Bcm4355C0 Firmware: 9.44.78.27.0.1.56

How to fix

Upgrade to a fixed version: Apple Iphone Os 11.0; Apple tvOS 11.0. Check the vendor advisory for mitigations.

References

http://packetstormsecurity.com/files/144329/Broadcom-802.11r-FT-Reassociation-Response-Overflows.html
http://www.securityfocus.com/bid/100984
https://bugs.chromium.org/p/project-zero/issues/detail?id=1291
https://lists.apple.com/archives/security-announce/2017/Sep/msg00007.html
https://lists.apple.com/archives/security-announce/2017/Sep/msg00009.html
https://source.android.com/security/bulletin/2017-09-01
https://support.apple.com/HT208112
https://support.apple.com/HT208113
https://support.apple.com/en-us/HT208112
https://support.apple.com/en-us/HT208113
http://packetstormsecurity.com/files/144329/Broadcom-802.11r-FT-Reassociation-Response-Overflows.html
http://www.securityfocus.com/bid/100984

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