CVE-2021-44964

Use after free in garbage collector and finalizer of lgc.c in Lua interpreter 5.4.0~5.4.3 allows attackers to perform Sandbox Escape via a crafted script file.

Weakness

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.

Affected Software

Potential Mitigations

References

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