urllib3 up to 1.26.18/2.2.1 Header Proxy-Authorization resource transfer

CVSS Meta Temp Score
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CTI Interest Score
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4.8$0-$5k0.00

Summaryinfo

A vulnerability described as problematic has been identified in urllib3 up to 1.26.18/2.2.1. Affected by this vulnerability is an unknown functionality of the component Header Handler. Executing a manipulation of the argument Proxy-Authorization can lead to resource transfer. This vulnerability is registered as CVE-2024-37891. It is possible to launch the attack remotely. No exploit is available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability classified as problematic was found in urllib3 up to 1.26.18/2.2.1. This vulnerability affects an unknown code block of the component Header Handler. The manipulation of the argument Proxy-Authorization with an unknown input leads to a resource transfer vulnerability. The CWE definition for the vulnerability is CWE-669. The product does not properly transfer a resource/behavior to another sphere, or improperly imports a resource/behavior from another sphere, in a manner that provides unintended control over that resource. As an impact it is known to affect confidentiality. CVE summarizes:

urllib3 is a user-friendly HTTP client library for Python. When using urllib3's proxy support with `ProxyManager`, the `Proxy-Authorization` header is only sent to the configured proxy, as expected. However, when sending HTTP requests *without* using urllib3's proxy support, it's possible to accidentally configure the `Proxy-Authorization` header even though it won't have any effect as the request is not using a forwarding proxy or a tunneling proxy. In those cases, urllib3 doesn't treat the `Proxy-Authorization` HTTP header as one carrying authentication material and thus doesn't strip the header on cross-origin redirects. Because this is a highly unlikely scenario, we believe the severity of this vulnerability is low for almost all users. Out of an abundance of caution urllib3 will automatically strip the `Proxy-Authorization` header during cross-origin redirects to avoid the small chance that users are doing this on accident. Users should use urllib3's proxy support or disable automatic redirects to achieve safe processing of the `Proxy-Authorization` header, but we still decided to strip the header by default in order to further protect users who aren't using the correct approach. We believe the number of usages affected by this advisory is low. It requires all of the following to be true to be exploited: 1. Setting the `Proxy-Authorization` header without using urllib3's built-in proxy support. 2. Not disabling HTTP redirects. 3. Either not using an HTTPS origin server or for the proxy or target origin to redirect to a malicious origin. Users are advised to update to either version 1.26.19 or version 2.2.2. Users unable to upgrade may use the `Proxy-Authorization` header with urllib3's `ProxyManager`, disable HTTP redirects using `redirects=False` when sending requests, or not user the `Proxy-Authorization` header as mitigations.

The advisory is shared for download at github.com. This vulnerability was named CVE-2024-37891 since 06/10/2024. The exploitation appears to be difficult. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 207856 (RHEL 8 / 9 : Red Hat Ansible Automation Platform 2.4 Product Security and Bug Fix Update (Moderate) (RHSA-2024:7312)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 1.26.19 or 2.2.2 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (207856) and CERT Bund (WID-SEC-2025-1567). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

  • Red Hat Enterprise Linux
  • Oracle MySQL
  • Ubuntu Linux
  • Oracle Linux
  • RESF Rocky Linux
  • Xerox FreeFlow Print Server

Productinfo

Name

Version

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.9
VulDB Meta Temp Score: 4.8

VulDB Base Score: 3.7
VulDB Temp Score: 3.6
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 6.5
NVD Vector: 🔍

CNA Base Score: 4.4
CNA Vector: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Resource transfer
CWE: CWE-669
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 207856
Nessus Name: RHEL 8 / 9 : Red Hat Ansible Automation Platform 2.4 Product Security and Bug Fix Update (Moderate) (RHSA-2024:7312)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: urllib3 1.26.19/2.2.2

Timelineinfo

06/10/2024 🔍
06/17/2024 +7 days 🔍
06/17/2024 +0 days 🔍
01/06/2026 +568 days 🔍

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2024-37891 (🔍)
GCVE (CVE): GCVE-0-2024-37891
GCVE (VulDB): GCVE-100-268840
CERT Bund: WID-SEC-2025-1567 - Oracle MySQL: Mehrere Schwachstellen

Entryinfo

Created: 06/17/2024 21:40
Updated: 01/06/2026 18:19
Changes: 06/17/2024 21:40 (62), 06/21/2024 06:41 (1), 09/27/2024 23:58 (3), 09/15/2025 06:53 (7), 09/17/2025 16:01 (1), 12/02/2025 18:00 (1), 01/06/2026 18:19 (11)
Complete: 🔍
Cache ID: 216::103

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