Karmada Tar Slips in CRDs archive extraction

Summary

Karmada is a Kubernetes management system that allows users to run cloud-native applications across multiple Kubernetes clusters and clouds. Prior to version 1.12.0, both in karmadactl and karmada-operator, it is possible to supply a filesystem path, or an HTTP(s) URL to retrieve the custom resource definitions(CRDs) needed by Karmada. The CRDs are downloaded as a gzipped tarfile and are vulnerable to a TarSlip vulnerability. An attacker able to supply a malicious CRD file into a Karmada initialization could write arbitrary files in arbitrary paths of the filesystem. From Karmada version 1.12.0, when processing custom CRDs files, CRDs archive verification is utilized to enhance file system robustness. A workaround is available. Someone who needs to set flag `--crd` to customize the CRD files required for Karmada initialization when using `karmadactl init` to set up Karmada can manually inspect the CRD files to check whether they contain sequences such as `../` that would alter file paths, to determine if they potentially include malicious files. When using karmada-operator to set up Karmada, one must upgrade one's karmada-operator to one of the fixed versions.