From b613a4239319e84332ec24acbb2cd0a6908f3643 Mon Sep 17 00:00:00 2001
From: Robby <robbyczgw@gmail.com>
Date: Wed, 28 Jan 2026 10:53:30 +0000
Subject: [PATCH] security(sandbox): add non-root user to Docker sandbox

Problem:
The sandbox container runs as root by default. If untrusted code runs
in the sandbox and a container escape vulnerability exists, the attacker
gains root access to the host.

Solution:
Add a non-privileged user following principle of least privilege:
```dockerfile
RUN useradd -m -s /bin/bash -u 1000 sandbox
USER sandbox
WORKDIR /home/sandbox
```

Fixes #3277 (partial)
[AI-assisted: lightly tested, code understood]
---
 Dockerfile.sandbox | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Dockerfile.sandbox b/Dockerfile.sandbox
index dec3f32d1..7a50d69a9 100644
--- a/Dockerfile.sandbox
+++ b/Dockerfile.sandbox
@@ -13,4 +13,8 @@ RUN apt-get update \
     ripgrep \
   && rm -rf /var/lib/apt/lists/*
 
+RUN useradd -m -s /bin/bash -u 1000 sandbox
+USER sandbox
+WORKDIR /home/sandbox
+
 CMD ["sleep", "infinity"]