Scapy before 2.8.0 contains an uncontrolled recursion vulnerability in the BER/ASN.1 decoder in scapy/asn1/ber.py that allows unauthenticated remote attackers to crash parsing applications. Attackers can send a single 833-byte packet with 250 nested ASN.1 SEQUENCE structures to trigger an unhandled RecursionError, terminating TLS, SNMP, X.509, or LDAP parsers even with safe=True.

Scapy before 2.8.0 contains a denial of service vulnerability in BERnumdec() and BERcodecOID.dodec() that allows remote attackers to exhaust CPU by supplying oversized OID arcs. Attackers can send ASN.1/BER data with many base-128 continuation bytes to cause quadratic CPU consumption or an uncaught ValueError crash on Python 3.11+.

Scapy before 2.7.0 contains an insecure deserialization vulnerability in the loadsession function that allows attackers to execute code by supplying a malicious pickle session file. Attackers can trick users into loading a crafted .pkl.gz file via the -s option or conf.session, executing embedded Python code through reduce().