Package Instance

Time-of-check Time-of-use (TOCTOU) Race Condition
libcurl can be told to save cookie, HSTS and/or alt-svc data to files. When
doing this, it called `stat()` followed by `fopen()` in a way that made it
vulnerable to a TOCTOU race condition problem.

By exploiting this flaw, an attacker could trick the victim to create or
overwrite protected files holding this data in ways it was not intended to.

Improper Authentication
An authentication bypass vulnerability exists in libcurl v8.0.0 where it reuses a previously established SSH connection despite the fact that an SSH option was modified, which should have prevented reuse. libcurl maintains a pool of previously used connections to reuse them for subsequent transfers if the configurations match. However, two SSH settings were omitted from the configuration check, allowing them to match easily, potentially leading to the reuse of an inappropriate connection.

Improper Authentication
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.