melange update-cache downloads URIs from build configs via io.Copy without any size limit or HTTP client timeout (pkg/renovate/cache/cache.go). An attacker-controlled URI in a melange config can cause unbounded disk writes, exhausting disk on the build runner. Affected versions <= 0.40.5.

Fix: Merged Acknowledgements

melange thanks Oleh Konko from 1seal for discovering and reporting this issue.

An attacker who can provide build input values, but not modify pipeline definitions, could execute arbitrary shell commands if the pipeline uses ${{vars.}} or ${{inputs.}} substitutions in working-directory. The field is embedded into shell scripts without proper quote escaping.

Fix: Fixed with e51ca30c, Released.

Acknowledgements

melange thanks Oleh Konko from 1seal for discovering and reporting this issue.