#VU92334 NULL pointer dereference in Linux kernel - CVE-2021-47592

Vulnerability identifier: #VU92334

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-2021-47592

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 NULL pointer dereference within the tc_setup_cls_u32(), tc_init(), tc_del_flow() and tc_add_vlan_flow() functions in drivers/net/ethernet/stmicro/stmmac/stmmac_tc.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, 5.15 rc1, 5.15 rc2, 5.15 rc3, 5.15 rc4, 5.15 rc5, 5.15 rc6, 5.15 rc7, 5.15.0, 5.15.1, 5.15.2, 5.15.3, 5.15.4, 5.15.5, 5.15.6, 5.15.7, 5.15.8, 5.15.9, 5.15.10, 5.16 rc1, 5.16 rc2, 5.16 rc3, 5.16 rc4, 5.16 rc5, 5.16 rc6, 5.16 rc8

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External links
https://git.kernel.org/stable/c/97cb5c82aa1dd85a39b1bd021c8b5f18af623779
https://git.kernel.org/stable/c/aeb7c75cb77478fdbf821628e9c95c4baa9adc63
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

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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.