Use-after-free in Linux kernel init

1) Use-after-free

EUVDB-ID: #VU90225

Risk: Low

CVSSv4.0: 5.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-47118

CWE-ID: CWE-416 - Use After Free

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a use-after-free error within the kernel_init_freeable() function in init/main.c. A local user can escalate privileges on the system.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Linux kernel: 4.4 - 5.13 rc5

CPE2.3

• cpe:2.3:o:linux_foundation:linux_kernel:4.4:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:4.4.0:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:4.4.0-57:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:4.4.1:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:4.4.2:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:4.4.3:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:4.4.4:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:4.4.5:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:4.4.6:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:4.4.7:*:*:*:*:*:*:*

External links

https://git.kernel.org/stable/c/764c2e892d1fe895392aff62fb353fdce43bb529
https://git.kernel.org/stable/c/f86c80515a8a3703e0ca2e56deb50fc2879c5ea4
https://git.kernel.org/stable/c/4dbd8808a591b49b717862e6e0081bcf14a87788
https://git.kernel.org/stable/c/d106f05432e60f9f62d456ef017687f5c73cb414
https://git.kernel.org/stable/c/2cd6eedfa6344f5ef5c3dac3aee57a39b5b46dff
https://git.kernel.org/stable/c/7178be006d495ffb741c329012da289b62dddfe6
https://git.kernel.org/stable/c/b8ff869f20152fbe66b6c2e2715d26a2f9897cca
https://git.kernel.org/stable/c/0711f0d7050b9e07c44bc159bbc64ac0a1022c7f
https://mirrors.edge.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.14.236
https://mirrors.edge.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.19.194
https://mirrors.edge.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.4.272
https://mirrors.edge.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.9.272
https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.10.43
https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.12.10
https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.13
https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.4.125

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.