# CVE-2026-32771: monitoring — Fixed in 0.2.2

🐹 Go

Not in CISA KEV

# CVE-2026-32771 — monitoring

[Fix: ctfer-io/monitoring@269dba1](https://github.com/ctfer-io/monitoring/commit/269dba165aa42210352628c0db6756f3b8fd3c8a)

CVE-2026-32771 is a Path Traversal vulnerability in github.com/ctfer-io/monitoring. A fix is available for github.com/ctfer-io/monitoring — see the affected versions and patch details below.

Monitoring is vulnerable to Archive Slip due to missing checks in sanitization

Also known as[GHSA-f7cq-gvh6-qr25](/vulnerability/GHSA-f7cq-gvh6-qr25)GO-2026-4712

Published

Mar 20, 2026

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 31, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

## Exploitation Status

### No confirmed exploitation observed yet

-   CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
-   CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-32771.

## EPSS Exploitation Probability

[via FIRST.org ↗](https://www.first.org/epss/)

0.7%probability of exploitation in next 30 days

Lower Risk\-0.04%

Lower risk than most CVEs52th percentile — riskier than 52% of all scored CVEsHighest risk

0.00%0.40%0.81%1.21%0.0%0.7%May 26Aug 26Oct 26

Probability of exploitation in the next 30 days, from [FIRST.org EPSS](https://www.first.org/epss/).

## Real-World Exposure

1 pkg affected

🐹`github.com/ctfer-io/monitoring`

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

## Description

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

```
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.  **Place the PoC tar on the PVC.** Any pod with write access to the `ReadWriteMany` PVC (or the compromised OTEL Collector itself) copies a `poc-path-traversal.tar` into the `/data/collector` mount path. The archive contains three real-looking OTLP telemetry files alongside two crafted entries with path-traversal names.
    
3.  **Run the extractor against the namespace:**
    
    ```
    extractor \
      --namespace monitoring \
      --pvc-name <signals-pvc-name> \
      --directory /home/user/extract-output
    ```
    
4.  **Observe the bypass.** `untar` processes the tar stream. For the malicious entries:
    
    ```
    // entry name: ../extract-outputevil/poc-proof.txt
    filepath.Join("/home/user/extract-output", "../extract-outputevil/poc-proof.txt")
      => "/home/user/extract-outputevil/poc-proof.txt"
    
    strings.HasPrefix("/home/user/extract-outputevil/poc-proof.txt",
                      "/home/user/extract-output")
      => true   // BUG: prefix collision; file lands OUTSIDE target dir
    ```
    
    Both malicious entries are written outside `/home/user/extract-output/`. The three legitimate OTLP files land correctly inside it.
    

### Impact

Successful exploitation gives an attacker arbitrary file write on the machine running the extractor. Real-world primitives include:

-   Overwriting `~/.bashrc` / `~/.zshrc` / `~/.profile` for RCE on next shell login
-   Appending to `~/.ssh/authorized_keys` for persistent SSH backdoor
-   Dropping a malicious entry into `~/.kube/config` to hijack cluster access
-   Writing crontab entries for persistent scheduled execution

The attack surface is widened by the default `ReadWriteMany` PVC access mode, which means any pod in the cluster with the PVC mounted can inject the payload — not just the OTEL Collector itself.

## Affected Packages

1 total 1 fixed

Ecosystem

Package

Vulnerable range

Fix

🐹Go

`github.com/ctfer-io/monitoring` 

all versions

0.2.2`go get github.com/ctfer-io/monitoring@v0.2.2`

## Affected Products

1 product · 1 configurations

Application

`monitoring`ctfer

< 0.2.2

range

## Detection & mitigation playbook

Open-source dependency

1.  ### Detect
    
    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/ctfer-io/monitoring, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
    
2.  ### Fix
    
    Update github.com/ctfer-io/monitoring to 0.2.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-32771 is resolved across your whole dependency graph.
    
3.  ### Workarounds
    
    Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.
    

## Frequently Asked Questions

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 trailin

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