Denial of service in Lua interpreter

Published: 2023-02-28 | Updated: 2023-05-03

Risk	Medium
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2021-44964 CVE-2021-44647
CWE-ID	CWE-416 CWE-843
Exploitation vector	Network
Public exploit	N/A
Vulnerable software Subscribe	Lua Universal components / Libraries / Scripting languages
Vendor	Lua

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Use-after-free

EUVDB-ID: #VU72632

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-44964

CWE-ID: CWE-416 - Use After Free

Exploit availability: No

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

External links

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

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.

2) Type Confusion

EUVDB-ID: #VU75704