cbcvebase.
CVE-2022-35411
published 2022-07-08

CVE-2022-35411: rpc.py through 0.6.0 allows Remote Code Execution because an unpickle occurs when the "serializer: pickle" HTTP header is sent. In other words, although JSON…

PriorityP179critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
EXPLOIT
EPSS
45.86%
98.7th percentile
rpc.py through 0.6.0 allows Remote Code Execution because an unpickle occurs when the "serializer: pickle" HTTP header is sent. In other words, although JSON (not Pickle) is the default data format, an unauthenticated client can cause the data to be processed with unpickle.

Affected

2 ranges
VendorProductVersion rangeFixed in
rpc.py_projectrpc.py0.4.2 – 0.6.0
rpc.py_projectrpc.py0.4.2 – 0.6.0

Detection & IOCsextracted from sources · hover to see the quote

otherserializer: pickle
  • Detect HTTP POST requests containing the header 'serializer: pickle' — this is the trigger for the unauthenticated RCE; no legitimate client should send this header unless explicitly configured.
  • Monitor HTTP POST requests to rpc.py endpoints (e.g. /sayhi) with the 'serializer: pickle' header and a binary (non-JSON) request body, which indicates a pickle payload delivery attempt.
  • Alert on pickle-deserialized payloads using Python's os.system reduce trick — the exploit constructs a PickleRce class whose __reduce__ returns os.system with an attacker-controlled command string.
  • Affected versions are rpc.py v0.4.2 through v0.6.0; flag any deployment of these versions exposed on a network interface.
  • ·JSON is the default serializer in rpc.py; the vulnerability is only exploitable when the server accepts and processes the client-supplied 'serializer: pickle' HTTP header without authentication or validation.

CVSS provenance

nvdv3.19.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
nvdv2.07.5HIGHAV:N/AC:L/Au:N/C:P/I:P/A:P
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