NULL pointer dereference in Linux kernel mptcp

1) NULL pointer dereference

EUVDB-ID: #VU92336

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-2021-47594

CWE-ID: CWE-476 - NULL Pointer Dereference

Exploit availability: No

Description

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

The vulnerability exists due to NULL pointer dereference within the mptcp_pm_nl_rm_addr_or_subflow() function in net/mptcp/pm_netlink.c. A local user can perform a denial of service (DoS) attack.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Linux kernel: 5.15 - 5.16 rc8

CPE2.3

• cpe:2.3:o:linux_foundation:linux_kernel:5.15:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:5.15:rc1:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:5.15:rc2:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:5.15:rc3:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:5.15:rc4:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:5.15:rc5:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:5.15:rc6:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:5.15:rc7:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:5.15.0:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:5.15.1:*:*:*:*:*:*:*

External links

https://git.kernel.org/stable/c/1456a0004cc54c58adb2501cb0c95dc8b3c83e9e
https://git.kernel.org/stable/c/b0cdc5dbcf2ba0d99785da5aabf1b17943805b8a
https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.15.11
https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.16

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.