TOS is an operating system for the OpenComputers Minecraft mod. Nothing it protects is real: the "machines" are blocks in a game world and the worst outcome of a break is a griefed base. It is written as though the stakes were real anyway, because that is the interesting part of the exercise, and because an OS that teaches sloppy habits is worse than no OS.

Read that as calibration, not as a shrug. Reports are welcome and get taken seriously.

Please do not open a public issue for a security problem.

Use GitHub's private vulnerability reporting: the Security tab on this repository → Report a vulnerability. That opens a private thread visible only to the maintainer.

If that is not available, open a public issue saying only that you have a security report and asking for a private channel — no details in the issue itself.

What helps, in rough order of usefulness:

• The branch and commit you looked at (dev is the source; main is a generated build, so line numbers differ between them).
• A reproduction. Off-box is fine and often better — most of TOS can be driven from plain Lua against fakes, which is how the test suite works.
• What an attacker gets. "An admin can overwrite the kernel" is a finding; "this function does not validate its argument" may not be, if nothing reachable passes it anything interesting.

In scope: the kernel, the sandbox and its capability gates, securefs, the network stack and its trust tiers, the package manager and its signature handling, the boot chain, and the installers.

Known and documented, so not news — but a concrete escalation through one of these still is:

• The boot chain is not cryptographically anchored. Write access to /init.lua, the manifest, or /etc/critical.bak is code execution before login. Documented in the manual's security model.
• securefs ACLs are not a physical boundary. Move the disk to another machine and they are gone. They are a policy inside a running TOS, not encryption.
• The software RNG is not a CSPRNG. Without a data card the pool is mixed from weak sources and says so; secret-bearing stores refuse rather than fall back to it.
• bootstrap.lua does not verify what it downloads. It trusts TLS and the integrity of the GitHub account. This is tracked work, not a decision.

Out of scope: anything requiring the attacker to already be the operator at the physical machine, and anything in the OpenComputers mod itself (report those upstream).

The current release on main. This is a hobby project with one maintainer; there is no backport branch and no patch-window promise.