CVE-2019-9500: Broadcom brcmfmac driver is vulnerable to a heap buffer overflow
If the Wake-up on Wireless LAN functionality is configured in the brcmfmac driver which only works with Broadcom FullMAC chipsets, a malicious event frame can be constructed to trigger an heap buffer overflow in the brcmfwowlndresults() function. This vulnerability can be exploited by compromised chipsets to compromise the host, or when used in combination with another brcmfmac driver flaw (CVE-2019-9503), can be used remotely. This can result in a remote denial of service (DoS). Due to the nature of the flaw, a remote privilege escalation cannot be fully ruled out, although we believe it is unlikely.
Introduced in:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3021ad9a4f009265e6063e617fb91306980af16c
An upstream patch:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1b5e2423164b3670e8bc9174e4762d297990deff
External References:
https://kb.cert.org/vuls/id/166939/
https://blog.quarkslab.com/reverse-engineering-broadcom-wireless-chipsets.html#cve-2019-9500-heap-buffer-overflow-in-brcmf-wowl-nd-results
https://www.bleepingcomputer.com/news/security/broadcom-wifi-driver-flaws-expose-computers-phones-iot-to-rce-attacks/
Other sources
If the Wake-up on Wireless LAN functionality is configured in the brcmfmac driver, which only works with Broadcom FullMAC chipsets, a malicious event frame can be constructed to trigger a heap buffer overflow in the brcmfwowlndresults() function. This vulnerability can be exploited by compromised chipsets to compromise the host, or when used in combination with another brcmfmac driver flaw (CVE-2019-9503), can be used remotely. This can result in a remote denial of service (DoS). Due to the nature of the flaw, a remote privilege escalation cannot be fully ruled out.
The Broadcom brcmfmac WiFi driver prior to commit 1b5e2423164b3670e8bc9174e4762d297990deff is vulnerable to a heap buffer overflow. If the Wake-up on Wireless LAN functionality is configured, a malicious event frame can be constructed to trigger an heap buffer overflow in the brcmfwowlndresults function. This vulnerability can be exploited with compromised chipsets to compromise the host, or when used in combination with CVE-2019-9503, can be used remotely. In the worst case scenario, by sending specially-crafted WiFi packets, a remote, unauthenticated attacker may be able to execute arbitrary code on a vulnerable system. More typically, this vulnerability will result in denial-of-service conditions.
Affected Software
Remediation
Information
Event History
Parent advisories
This vulnerability appears in the following advisories.
Peer vulnerabilities
Found alongside the following vulnerabilities.
Frequently Asked Questions
What is the severity of CVE-2019-9500?
CVE-2019-9500 has been rated as a high-severity vulnerability due to the potential for remote code execution via a heap buffer overflow.
How do I fix CVE-2019-9500?
To fix CVE-2019-9500, update the Linux kernel to the appropriate patched version specified by your distribution.
What systems are affected by CVE-2019-9500?
CVE-2019-9500 affects systems using the brcmfmac driver with Broadcom FullMAC chipsets, particularly within certain Linux kernel versions.
Can CVE-2019-9500 be exploited remotely?
Yes, CVE-2019-9500 can be exploited remotely by constructing malicious event frames.
What is the impact of exploiting CVE-2019-9500?
Exploiting CVE-2019-9500 can lead to a breach of system integrity, allowing attackers to execute arbitrary code on the affected device.