#VU72632 Use-after-free in Lua - CVE-2021-44964

Vulnerability identifier: #VU72632

Vulnerability risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-44964

CWE-ID: CWE-416

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Lua
Universal components / Libraries / Scripting languages

Vendor: Lua

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a use-after-free error in garbage collector and finalizer of lgc.c. A remote attacker can pass specially crafted script file to the application, trigger a use-after-free error and perform a denial of service (DoS) attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Lua: 5.4.0 - 5.4.3

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External links
https://lua-users.org/lists/lua-l/2021-12/msg00030.html
https://lua-users.org/lists/lua-l/2021-12/msg00015.html
https://github.com/Lua-Project/lua-5.4.4-sandbox-escape-with-new-vulnerability
https://lua-users.org/lists/lua-l/2021-11/msg00186.html
https://lua-users.org/lists/lua-l/2021-12/msg00007.html

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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 Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.