vulnerability

Amazon Linux 2023: CVE-2023-27535: Medium priority package update for curl

Severity
7
CVSS
(AV:N/AC:M/Au:N/C:C/I:N/A:N)
Published
Mar 20, 2023
Added
Feb 17, 2025
Modified
Jul 9, 2025

Description

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.
A flaw was found in the Curl package. Libcurl keeps previously used connections in a connection pool for subsequent transfers to reuse if one of them matches the setup. However, several FTP settings were left out from the configuration match checks, making them match too easily. The problematic settings are `CURLOPT_FTP_ACCOUNT`, `CURLOPT_FTP_ALTERNATIVE_TO_USER`, `CURLOPT_FTP_SSL_CCC` and `CURLOPT_USE_SSL` level.

Solutions

amazon-linux-2023-upgrade-curlamazon-linux-2023-upgrade-curl-debuginfoamazon-linux-2023-upgrade-curl-debugsourceamazon-linux-2023-upgrade-curl-minimalamazon-linux-2023-upgrade-curl-minimal-debuginfoamazon-linux-2023-upgrade-libcurlamazon-linux-2023-upgrade-libcurl-debuginfoamazon-linux-2023-upgrade-libcurl-develamazon-linux-2023-upgrade-libcurl-minimalamazon-linux-2023-upgrade-libcurl-minimal-debuginfo
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