CVE-2021-3609: Race Condition
.A flaw was found in the CAN BCM networking protocol in the Linux kernel, where a local attacker can abuse a flaw in the CAN subsystem to corrupt memory, crash the system or escalate privileges. This race condition in net/can/bcm.c in the Linux kernel allows for local privilege escalation to root.
Other sources
A race condition occurs between bcmrelease() and bcmrxhandler(). When a message is received in bcmrxhandler(), the socket can be closed in bcmrelease() which will free the struct bcmsock and struct bcmop. This leads to various use-after-free's in bcmrxhandler() and depending on the provided flags, also in bcmrxtimeouthandler(). The use-after-free's in combination with a heap spray may lead to sensitive socket data being overwritten, resulting in local privilege escalation.
— Red Hat
Linux Kernel could allow a local authenticated attacker to gain elevated privileges on the system, caused by a race condition in net/can/bcm.c. By sending a specially-crafted request, an authenticated attacker could exploit this vulnerability to gain elevated privileges as root.
— IBM
Affected Software
Remediation
Information
Event History
Parent advisories
This vulnerability appears in the following advisories.
Frequently Asked Questions
What is the severity of CVE-2021-3609?
CVE-2021-3609 has been classified with a high severity level due to its potential for local privilege escalation.
How do I fix CVE-2021-3609?
To mitigate CVE-2021-3609, update to the latest kernel version as specified in the remediation instructions from your vendor.
What types of systems are affected by CVE-2021-3609?
CVE-2021-3609 affects various Linux kernel versions, particularly those in Red Hat and Debian distributions.
Can CVE-2021-3609 be exploited remotely?
No, CVE-2021-3609 requires local access for exploitation, making it a local privilege escalation vulnerability.
What happens if CVE-2021-3609 is successfully exploited?
If exploited, CVE-2021-3609 could lead to memory corruption, a system crash, or privilege escalation to root.