CVE-2024-28185
Judge0 vulnerable to Sandbox Escape via Symbolic Link
In short
Judge0's sandbox can be escaped by creating symbolic links that trick the system into writing files outside the intended sandbox directory, allowing an attacker to execute code anywhere on the server.
Technical detail
Judge0 fails to validate symlinks in the sandbox directory; an attacker can pre-create a symlink named `run_script` that causes `f.write()` operations to target arbitrary files on the host system, enabling arbitrary file write and remote code execution outside sandbox confinement.
Summary generated and translated by AI from the official description.
Judge0 is an open-source online code execution system. The application does not account for symlinks placed inside the sandbox directory, which can be leveraged by an attacker to write to arbitrary files and gain code execution outside of the sandbox. When executing a submission, Judge0 writes a `run_script` to the sandbox directory. The security issue is that an attacker can create a symbolic link (symlink) at the path `run_script` before this code is executed, resulting in the `f.write` writing to an arbitrary file on the unsandboxed system. An attacker can leverage this vulnerability to overwrite scripts on the system and gain code execution outside of the sandbox.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Affected products
judge0 · judge0Want to know if your infrastructure is exposed to this?
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