Redis is an open source, in-memory database that persists on disk. In
affected versions specially crafted Lua scripts executing in Redis can
cause the heap-based Lua stack to be overflowed, due to incomplete checks
for this condition. This can result with heap corruption and potentially
remote code execution. This problem exists in all versions of Redis with
Lua scripting support, starting from 2.6. The problem is fixed in versions
6.2.6, 6.0.16 and 5.0.14. For users unable to update an additional
workaround to mitigate the problem without patching the redis-server
executable is to prevent users from executing Lua scripts. This can be done
using ACL to restrict EVAL and EVALSHA commands.