CVE-2023-24329

HIGH

Python < 3.11.4 - URL Blocklist Bypass via Leading Blank Characters in urllib.parse

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 5 public exploits for CVE-2023-24329. PoCs published by JawadPy, jithinodattu, PenTestMano.

AI-analyzed exploit summary The repository contains functional exploit code for CVE-2023-24329, demonstrating a URL parsing bypass in Python's urllib.parse before version 3.11.4. The PoC shows how leading whitespace in a URL can bypass blocked list checks due to incorrect normalization.

Description

An issue in the urllib.parse component of Python before 3.11.4 allows attackers to bypass blocklisting methods by supplying a URL that starts with blank characters.

Exploits (5)

github WORKING POC 1 stars
by JawadPy · pythonpoc
https://github.com/JawadPy/CVE-Exploit-Collection/tree/main/CVE-2023-24329-Exploit

The repository contains functional exploit code for CVE-2023-24329, demonstrating a URL parsing bypass in Python's urllib.parse before version 3.11.4. The PoC shows how leading whitespace in a URL can bypass blocked list checks due to incorrect normalization.

Classification
Working Poc 90%
Attack Type
Auth Bypass
Complexity
Trivial
Reliability
Reliable
Target: Python urllib.parse (versions before 3.11.4)
No auth needed
Prerequisites: Python environment with urllib.parse < 3.11.4
devstral-2 · analyzed Feb 27, 2026 Full analysis →
nomisec WORKING POC
by jithinodattu · poc
https://github.com/jithinodattu/CVE-2023-24329-lab

This repository contains a functional exploit PoC for CVE-2023-24329, demonstrating a parser differential vulnerability in Python's urllib.parse.urlparse() that allows bypass of URL scheme filters. The lab includes a vulnerable API, an internal service, and an attacker script to showcase local file read and SSRF attacks.

Classification
Working Poc 100%
Attack Type
Ssrf | Info Leak
Complexity
Moderate
Reliability
Reliable
Target: Python < 3.11.4
No auth needed
Prerequisites: Docker · Python environment
devstral-2 · analyzed Apr 18, 2026 Full analysis →
nomisec WORKING POC
by PenTestMano · poc
https://github.com/PenTestMano/CVE-2023-24329-Exploit

This repository demonstrates a URL parsing bypass in Python's urllib.parse (CVE-2023-24329) where leading whitespace in a URL circumvents blocked list checks. The PoC shows how a URL with leading spaces evades detection by urllib.parse.urlparse().geturl().

Classification
Working Poc 95%
Attack Type
Auth Bypass
Complexity
Trivial
Reliability
Reliable
Target: Python urllib.parse (versions before 3.11.4)
No auth needed
Prerequisites: Python environment with urllib.parse (version < 3.11.4)
devstral-2 · analyzed Feb 18, 2026 Full analysis →
nomisec WORKING POC
by Pandante-Central · poc
https://github.com/Pandante-Central/CVE-2023-24329-codeql-test

The repository contains a functional PoC for CVE-2023-24329, demonstrating a URL parsing vulnerability in Python's urllib.parse. The exploit shows how leading whitespace or '+' characters can bypass hostname blocking checks, potentially leading to SSRF.

Classification
Working Poc 90%
Attack Type
Ssrf
Complexity
Trivial
Reliability
Reliable
Target: Python urllib.parse (versions affected by CVE-2023-24329)
No auth needed
Prerequisites: Python environment with vulnerable urllib.parse
devstral-2 · analyzed Feb 18, 2026 Full analysis →
nomisec WORKING POC
by H4R335HR · poc
https://github.com/H4R335HR/CVE-2023-24329-PoC

This PoC demonstrates CVE-2023-24329, a Python urllib parsing flaw where leading spaces in URLs bypass blocklists for schemes and hostnames. It includes a functional exploit that checks Python version vulnerability and allows testing of bypass techniques.

Classification
Working Poc 95%
Attack Type
Ssrf
Complexity
Trivial
Reliability
Reliable
Target: Python urllib (versions before 3.7.17, 3.8.17, 3.9.17, 3.10.12, 3.11.4, 3.12)
No auth needed
Prerequisites: Python environment with vulnerable urllib version
devstral-2 · analyzed Feb 18, 2026 Full analysis →

References (29)

Core 29
Core References
Exploit, Mitigation, Technical Description, Third Party Advisory
https://pointernull.com/security/python-url-parse-problem.html
Third Party Advisory, US Government Resource third-party-advisory
https://www.kb.cert.org/vuls/id/127587

Scores

CVSS v3 7.5
EPSS 0.2046
EPSS Percentile 97.2%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact partial

Details

CWE
CWE-20
Status published
Products (8)
fedoraproject/fedora 36
fedoraproject/fedora 37
fedoraproject/fedora 38
netapp/active_iq_unified_manager (2 CPE variants)
netapp/management_services_for_element_software
netapp/management_services_for_netapp_hci
netapp/ontap_select_deploy_administration_utility
python/python < 3.7.17
Published Feb 17, 2023
Tracked Since Feb 18, 2026