#VU91052 Use-after-free in Linux kernel - CVE-2021-47521

Vulnerability identifier: #VU91052

Vulnerability 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-2021-47521

CWE-ID: CWE-416

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 escalate privileges on the system.

The vulnerability exists due to a use-after-free error within the ems_pcmcia_add_card() function in drivers/net/can/sja1000/ems_pcmcia.c. A local user can escalate privileges on the system.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Linux kernel: All versions

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External links
https://git.kernel.org/stable/c/cbd86110546f7f730a1f5d7de56c944a336c15c4
https://git.kernel.org/stable/c/1dd5b819f7e406dc15bbc7670596ff25261aaa2a
https://git.kernel.org/stable/c/c8718026ba287168ff9ad0ccc4f9a413062cba36
https://git.kernel.org/stable/c/ccf070183e4655824936c0f96c4a2bcca93419aa
https://git.kernel.org/stable/c/1a295fea90e1acbe80c6d4940f5ff856edcd6bec
https://git.kernel.org/stable/c/923f4dc5df679f678e121c20bf2fd70f7bf3e288
https://git.kernel.org/stable/c/474f9a8534f5f89841240a7e978bafd6e1e039ce
https://git.kernel.org/stable/c/3ec6ca6b1a8e64389f0212b5a1b0f6fed1909e45

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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.