An authentication bypass vulnerability exists in libcurl <8.0.0 in the FTP connection reuse feature that can result in wrong credentials being used during subsequent transfers. Previously created connections are kept in a connection pool for reuse if they match the current setup. However, certain FTP settings such as CURLOPT_FTP_ACCOUNT, CURLOPT_FTP_ALTERNATIVE_TO_USER, CURLOPT_FTP_SSL_CCC, and CURLOPT_USE_SSL were not included in the configuration match checks, causing them to match too easily. This could lead to libcurl using the wrong credentials when performing a transfer, potentially allowing unauthorized access to sensitive information.

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Advisories
Source ID Title
Debian DLA Debian DLA DLA-3398-1 curl security update
EUVD EUVD EUVD-2023-31290 An authentication bypass vulnerability exists in libcurl <8.0.0 in the FTP connection reuse feature that can result in wrong credentials being used during subsequent transfers. Previously created connections are kept in a connection pool for reuse if they match the current setup. However, certain FTP settings such as CURLOPT_FTP_ACCOUNT, CURLOPT_FTP_ALTERNATIVE_TO_USER, CURLOPT_FTP_SSL_CCC, and CURLOPT_USE_SSL were not included in the configuration match checks, causing them to match too easily. This could lead to libcurl using the wrong credentials when performing a transfer, potentially allowing unauthorized access to sensitive information.
Ubuntu USN Ubuntu USN USN-5964-1 curl vulnerabilities
Ubuntu USN Ubuntu USN USN-5964-2 curl vulnerabilities
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Mon, 09 Jun 2025 15:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: hackerone

Published:

Updated: 2025-06-09T14:47:57.951Z

Reserved: 2023-03-02T00:00:00.000Z

Link: CVE-2023-27535

cve-icon Vulnrichment

Updated: 2024-08-02T12:16:35.540Z

cve-icon NVD

Status : Modified

Published: 2023-03-30T20:15:07.483

Modified: 2025-06-09T15:15:28.903

Link: CVE-2023-27535

cve-icon Redhat

Severity : Moderate

Publid Date: 2023-03-20T00:00:00Z

Links: CVE-2023-27535 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses