#VU87990 NULL pointer dereference in Linux kernel - CVE-2021-46904

Vulnerability identifier: #VU87990

Vulnerability risk: Low

CVSSv4.0: 4.3 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-46904

CWE-ID: CWE-476

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Linux kernel
Operating systems & Components / Operating system

Vendor: Linux Foundation

Description

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to a NULL pointer dereference error during tty device unregistration
 within the get_free_serial_index() function in drivers/net/usb/hso.c. A local user can perform a denial of service (DoS) attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Linux kernel: All versions

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External links
https://git.kernel.org/stable/c/a462067d7c8e6953a733bf5ade8db947b1bb5449
https://git.kernel.org/stable/c/145c89c441d27696961752bf51b323f347601bee
https://git.kernel.org/stable/c/caf5ac93b3b5d5fac032fc11fbea680e115421b4
https://git.kernel.org/stable/c/92028d7a31e55d53e41cff679156b9432cffcb36
https://git.kernel.org/stable/c/4a2933c88399c0ebc738db39bbce3ae89786d723
https://git.kernel.org/stable/c/dc195928d7e4ec7b5cfc6cd10dc4c8d87a7c72ac
https://git.kernel.org/stable/c/388d05f70f1ee0cac4a2068fd295072f1a44152a
https://git.kernel.org/stable/c/8a12f8836145ffe37e9c8733dce18c22fb668b66

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Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.