GHSA-cq46-m9x9-j8w2: Scapy Scapy Session Loading Vulnerable To Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-cq46-m9x9-j8w2",
  "modified" : "2025-10-23T20:10:45Z",
  "published" : "2025-10-22T16:45:49Z",
  "aliases" : [ ],
  "summary" : "Scapy Session Loading Vulnerable to Arbitrary Code Execution via Untrusted Pickle Deserialization",
  "details" : "### Summary\n\nAn unsafe deserialization vulnerability in Scapy <v2.7.0 allows attackers to execute arbitrary code **when a malicious session file is locally loaded via the `-s` option**. This requires convincing a user to manually load a malicious session file.\n\n---\n\n### Details\n\nScapy’s interactive shell supports session loading using gzip-compressed pickle files:\n\n```bash\n./run_scapy -s <session_file.pkl.gz>\n```\n\nInternally, this triggers:\n\n```python\n# main.py\nSESSION = pickle.load(gzip.open(session_name, \"rb\"))\n```\n\nSince no validation or restriction is performed on the deserialized object, **any code embedded via `__reduce__()` will be executed immediately**. This makes it trivial for an attacker to drop a malicious `.pkl.gz` in a shared folder and have it executed by unsuspecting users.\n\nThe vulnerability exists in the `load_session` function, which deserializes data using `pickle.load()` on `.pkl.gz` files provided via the `-s` CLI flag or programmatically through `conf.session`.\n\n**Affected lines in source code**:\nhttps://github.com/secdev/scapy/blob/master/scapy/main.py#L569-L572\n\n```python\ntry:\n    s = pickle.load(gzip.open(fname, \"rb\"))\nexcept IOError:\n    try:\n        s = pickle.load(open(fname, \"rb\"))\n```\n\n### Impact\n\nThis is a classic deserialization vulnerability which leads to Code Execution (CE) when untrusted data is deserialized.\n\nAny user who can trick another user into loading a crafted `.pkl.gz` session file (e.g. via `-s` option) can execute arbitrary Python code.\n\n- **Vulnerability type:** Insecure deserialization (Python `pickle`)\n- **CWE**: [CWE-502: Deserialization of Untrusted Data](https://cwe.mitre.org/data/definitions/502.html)\n- **CVSS v4.0 Vector**: `CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`\n- **CVSS Score**: 5.4 (Medium)\n- **Impact:** Arbitrary Code Execution\n- **Attack vector:** Local or supply chain (malicious `.pkl.gz`)\n- **Affected users:** Any user who loads session files (even interactively)\n- **Affected version:** **Scapy v2.6.1**\n\n---\n\n### Mitigations\n\n- Do not use 'sessions' (the -s option when launching Scapy).\n- Use the Scapy 2.7.0+ where the session mechanism has been removed.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "scapy"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "2.6.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/secdev/scapy/security/advisories/GHSA-cq46-m9x9-j8w2"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/secdev/scapy/commit/13621d1145b3435e9d03caf20997107a84435c0b"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/secdev/scapy"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-502" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-10-22T16:45:49Z",
    "nvd_published_at" : null
  }
}