Vulnerability in picklescan (CVE-2025-71322)
Summary
Vulnerability in picklescan (CVE-2025-71322). Successful exploitation can lead to full system takeover. Exploitable via pty. Mitigation: upgrade to 0.0.33 or later.
Original description
The description as published by the source.
Summary
The vulnerability allows malicious actors to bypass PickleScan's unsafe globals check, leading to potential arbitrary code execution. The issue stems from the absence of the pty library (more specifically, of the pty.spawn function) from PickleScan's list of unsafe globals. This vulnerability allows attackers to disguise malicious pickle payloads within files that would otherwise be scanned for pickle-based threats.
Details
For 2025's HeroCTF, there was a challenge named Irreductible 2 where players would need to bypass the latest versions of PickleScan and Fickling to gain code execution. The challenge writeup, files and solve script have all been released.
The intended way was to use pty.spawn but some players found alternative solutions.
PoC
- Run the following Python code to generate the PoC pickle file.
import pickle
command = b"/bin/sh"
payload = b"".join(
[
pickle.PROTO + pickle.pack("B", 4),
pickle.MARK,
pickle.GLOBAL + b"pty\n" + b"spawn\n",
pickle.EMPTY_LIST,
pickle.SHORT_BINUNICODE + pickle.pack("B", len(command)) + command,
pickle.APPEND,
# Additional arguments can b…
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-2025-71322 has been found in picklescan.
Attackers can target a specific entry point like pty over the network to misuse the product.
Successful exploitation can lead to full system takeover. CVSS score: 8.8/10.
What to do: upgrade picklescan to 0.0.33 or later.
If unsure, ask your IT team or search "picklescan CVE-2025-71322" on the vendor's site.
CVE-2025-71322 (picklescan) — CWE-693 / CVSS v3 8.8
Attack vector: remote (network-reachable) / unauthenticated
Attack surface: pty / pty.spawn
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-693) exists in picklescan. Attackers reach the vulnerable code path via pty without authentication.
Check the vendor advisory for the affected versions of picklescan. Attack surface: pty / pty.spawn.
Severity: High (CVSS 8.8/10). 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