#VU50900 Heap-based buffer overflow in VMware ESXi - CVE-2021-21974

Vulnerability identifier: #VU50900

Vulnerability risk: High

CVSSv4.0: 8.7 [CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:A/U:Amber]

CVE-ID: CVE-2021-21974

CWE-ID: CWE-122

Exploitation vector: Local network

Exploit availability: Yes

Vulnerable software:
VMware ESXi
Operating systems & Components / Operating system

Vendor: VMware, Inc

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error when processing packets within the OpenSLP service. A remote non-authenticated attacker on the local network can send specially crafted SLP messages to port 427/tcp, trigger a heap-based buffer overflow and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Note, the vulnerability is being actively exploited in the wild.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

VMware ESXi: ESXi_7.0.0-1.20.16321839 - 7.0

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External links
https://www.vmware.com/security/advisories/VMSA-2021-0002.html
https://kb.vmware.com/s/article/76372
https://www.zerodayinitiative.com/advisories/ZDI-21-250/

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the local network (LAN).

Is there known malware, which exploits this vulnerability?

Yes. This vulnerability is being exploited in the wild.