Please report potential security issues with the Fennel compiler or web site to [email protected] and [email protected].

Sensitive reports may be encrypted with the PGP key listed below.

From version 0.10.0 onward, Fennel releases and tags have been signed with the PGP key 8F2C85FFC1EBC016A3B683DE8BD38C28CCFD2DA6. Before that the key 20242BACBBE95ADA22D0AFD7808A33D379C806C3 was used.

To verify:

$ curl https://technomancy.us/8F2C85FFC1EBC016A3B683DE8BD38C28CCFD2DA6.txt | gpg --import -
$ gpg --verify fennel-1.2.0.asc

From 1.0 onwards, releases are also signed with .sig files using SSH keys:

$ curl -O allowed https://fennel-lang.org/downloads/allowed_signers
$ ssh-keygen -Y verify -f allowed -I [email protected] -n file -s fennel-1.2.0.sig < fennel-1.2.0

You can compare the key in the allowed file with the keys published at technomancy.us, SourceHut, or GitHub.

In versions from 1.0.0 to 1.3.1, it was possible for code running in the compiler sandbox to call un-sandboxed functions from applications or Fennel libraries when running with metadata enabled. This could result in RCE when evaluating untrusted code in a way that relied on the sandbox for services running with metadata enabled.

In addition, even when metadata was disabled, it was still possible for sandboxed code to trigger loading of a module already on the load path. In most cases if an attacker can get a file on the load-path then they've already won, but in the context of tools that run static analysis on untrusted code, this could result in a vulnerability.

Versions prior to 1.0.0 did not sandbox macros.