The CTFer.io Monitoring component is in charge of the collection, process and storage of various signals (i.e. logs, metrics and distributed traces). In versions prior to 0.2.2, the sanitizeArchivePath function in pkg/extract/extract.go (lines 248–254) is vulnerable to Path Traversal due to a missing trailing path separator in the strings.HasPrefix check. The extractor allows arbitrary file writes (e.g., overwriting shell configs, SSH keys, kubeconfig, or crontabs), enabling RCE and persistent backdoors. The attack surface is further amplified by the default ReadWriteMany PVC access mode, which lets any pod in the cluster inject a malicious payload. This issue has been fixed in version 0.2.2.
Affected: Go: github.com/ctfer-io/monitoring
The `sanitizeArchivePath` function in `pkg/extract/extract.go` (lines 248–254) is vulnerable to a path traversal bypass due to a missing trailing path separator in the `strings.HasPrefix` check. A crafted tar archive can write files outside the intended destination directory when using the `extractor` CLI tool or the `extract.DumpOTelCollector` library function.
## Vulnerable Code
File: `pkg/extract/extract.go`, lines 248–254
```go func sanitizeArchivePath(d, t string) (v string, err error) { v = filepath.Join(d, t) if strings.HasPrefix(v, filepath.Clean(d)) { // ← missing trailing separator return v, nil } return "", fmt.Errorf("filepath is tainted: %s", t) } ```
The function is called at line 219 inside `untar`, which is invoked by `copyFromPod` (line 205) during the Cold Extract data dump workflow.
## Root Cause
`strings.HasPrefix(v, filepath.Clean(d))` does not append a trailing `/` to the directory prefix, causing a **directory name prefix collision**. If the destination is `/home/user/extract-output` and a tar entry is named `../extract-outputevil/pwned`, the joined path `/home/user/extract-outputevil/pwned` passes the prefix check — it starts with `/home/user/extract-output` — even though it is entirely outside the intended directory.
## Steps to Reproduce
1. **Deploy the monitoring stack** with `ColdExtract: true`. The OTEL Collector begins writing signal data (`otel_traces`, `otel_metrics`, `otel_logs`) to the shared PVC.
2. **Plac…