Fix stack trace leaked in error response in Sails.js

Returning an error's `.stack` to the client exposes absolute file paths, dependency versions, and internal call structure. Attackers use it to map the application and to fingerprint vulnerable dependency versions. Log the stack server-side and return a generic message.

high likely Sails.js CWE-209 / OWASP A05:2021

The vulnerable pattern in Sails.js

HIGH likely Stack trace leaked in error response A05:2021 api/controllers/AuthController.js:39:44 37 │ } catch (err) { 38 │ // stack-trace-leak: the client learns the file layout. 39 │ return res.status(500).json({ error: err.stack }) │ ~~~~~~~~~ leaks internal stack trace to the client 40 │ } 41 │ },

This finding comes from the Sails.js fixture in the owlwarden test suite, in /auth. Stack traces expose absolute file paths, dependency versions, and internal call structure - enough to fingerprint the stack and locate other weaknesses.

The corrected handler

Log server-side and send a generic body.

sails.log.error(err)
return res.status(500).json({ error: 'Internal Server Error' })

If you are not using Sails.js

Log the error server-side and return a generic message to the client.

Check your own repository

npx owlwarden scan
npx owlwarden explain stack-trace-leak

Runs on your machine. No account, no telemetry, no network unless you ask. In CI, SARIF uploads to code scanning and the exit code is the gate.

Other Sails.js checks

Rules with a tested Sails.js example.

stack-trace-leak for every framework / All rules / owlwarden