GHSA-cq46-m9x9-j8w2
Scapy Session Loading Vulnerable to Arbitrary Code Execution via Untrusted Pickle Deserialization
Blast Radius
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Description
Summary
An 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.
Details
Scapy’s interactive shell supports session loading using gzip-compressed pickle files:
./run_scapy -s <session_file.pkl.gz>
Internally, this triggers:
# main.py
SESSION = pickle.load(gzip.open(session_name, "rb"))
Since 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.
The 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.
Affected lines in source code: https://github.com/secdev/scapy/blob/master/scapy/main.py#L569-L572
try:
s = pickle.load(gzip.open(fname, "rb"))
except IOError:
try:
s = pickle.load(open(fname, "rb"))
Impact
This is a classic deserialization vulnerability which leads to Code Execution (CE) when untrusted data is deserialized.
Any user who can trick another user into loading a crafted .pkl.gz session file (e.g. via -s option) can execute arbitrary Python code.
- Vulnerability type: Insecure deserialization (Python
pickle) - CWE: CWE-502: Deserialization of Untrusted Data
- 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 - CVSS Score: 5.4 (Medium)
- Impact: Arbitrary Code Execution
- Attack vector: Local or supply chain (malicious
.pkl.gz) - Affected users: Any user who loads session files (even interactively)
- Affected version: Scapy v2.6.1
Mitigations
- Do not use 'sessions' (the -s option when launching Scapy).
- Use the Scapy 2.7.0+ where the session mechanism has been removed.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | scapy | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for scapy. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of scapy has shipped for GHSA-cq46-m9x9-j8w2 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-cq46-m9x9-j8w2 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-cq46-m9x9-j8w2. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-cq46-m9x9-j8w2 in your dependencies?
O3 detects GHSA-cq46-m9x9-j8w2 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.