Summary
Scapy Session Loading Vulnerable to Arbitrary Code Execution via Untrusted Pickle Deserialization
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"))
Mitigations
- Do not use 'sessions' (the -s option when launching Scapy).
- Use the Scapy 2.7.0+ where the session mechanism has been removed.
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
Untrusted serialized data is processed by a deserializer that can instantiate arbitrary objects or execute code as a side effect. Typical impact: arbitrary code execution or logic abuse.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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See it in your environmentNew to Kodem? Get a demo →Remediation advice
In the interim: Avoid deserializing data from untrusted sources. If deserialization is required, use a format that does not support code execution and validate the input strictly.
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is GHSA-CQ46-M9X9-J8W2? GHSA-CQ46-M9X9-J8W2 is a medium-severity insecure deserialization vulnerability in scapy (pip), affecting versions <= 2.6.1. No fixed version is listed yet. Untrusted serialized data is processed by a deserializer that can instantiate arbitrary objects or execute code as a side effect.
- Which versions of scapy are affected by GHSA-CQ46-M9X9-J8W2? scapy (pip) versions <= 2.6.1 is affected.
- Is there a fix for GHSA-CQ46-M9X9-J8W2? No fixed version is listed for GHSA-CQ46-M9X9-J8W2 yet. Monitor the advisory for updates and apply mitigations in the interim.
- Is GHSA-CQ46-M9X9-J8W2 exploitable, and should I be worried? Whether GHSA-CQ46-M9X9-J8W2 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether GHSA-CQ46-M9X9-J8W2 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix GHSA-CQ46-M9X9-J8W2? No fixed version is listed yet. In the interim: Avoid deserializing data from untrusted sources. If deserialization is required, use a format that does not support code execution and validate the input strictly.