What’s Vulnerable › Vulnerabilities

CVE-2021-43519

• Severity: medium (CVSS 5.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.2% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-11-09 · updated 2026-06-17
• Weakness: CWE-674

Description

Stack overflow in lua_resume of ldo.c in Lua Interpreter 5.1.0~5.4.4 allows attackers to perform a Denial of Service via a crafted script file.

Affected products

• Fedoraproject Fedora: 35
• Lua: from 5.1.0 before 5.3.5; from 5.4.0 before 5.4.4 — fixed in 5.3.5, 5.4.4

How to fix

Upgrade to a fixed version: Lua 5.3.5, 5.4.4. Check the vendor advisory for mitigations.

References

• http://lua-users.org/lists/lua-l/2021-10/msg00123.html
• http://lua-users.org/lists/lua-l/2021-11/msg00015.html
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/C7XHFYHGSZKL53VCLSJSAJ6VMFGAIXKO/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/P3EMGAQ5Y6GXJLY4K5DUOOEQT4MZ4J4F/
• http://lua-users.org/lists/lua-l/2021-10/msg00123.html
• http://lua-users.org/lists/lua-l/2021-11/msg00015.html
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/C7XHFYHGSZKL53VCLSJSAJ6VMFGAIXKO/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/P3EMGAQ5Y6GXJLY4K5DUOOEQT4MZ4J4F/

Get alerted when CVE-2021-43519 or the next vulnerability affects your stack