A curl security update has been released for Debian GNU/Linux 8 and 9 Extended LTS to address several security vulnerabilities.

ELA-831-1 curl security update

Package : curl
Version : 7.38.0-4+deb8u26 (jessie), 7.52.1-5+deb9u19 (stretch)

Related CVEs :
CVE-2023-27533
CVE-2023-27535
CVE-2023-27536
CVE-2023-27538

Several security vulnerabilities have been found in cURL, an easy-to-use client-side
URL transfer library.

CVE-2023-27533
A vulnerability in input validation exists in curl during
communication using the TELNET protocol. It may allow an attacker to pass on
maliciously crafted user name and "telnet options" during server
negotiation. The lack of proper input scrubbing allows an attacker to send
content or perform option negotiation without the application's intent.
This vulnerability could be exploited if an application allows user input,
thereby enabling attackers to execute arbitrary code on the system.

CVE-2023-27535
An authentication bypass vulnerability exists in libcurl 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.

CVE-2023-27536
An authentication bypass vulnerability exists in libcurl in the
connection reuse feature which can reuse previously established connections
with incorrect user permissions due to a failure to check for changes in
the CURLOPT_GSSAPI_DELEGATION option. This vulnerability affects
krb5/kerberos/negotiate/GSSAPI transfers and could potentially result in
unauthorized access to sensitive information. The safest option is to not
reuse connections if the CURLOPT_GSSAPI_DELEGATION option has been changed.

CVE-2023-27538
An authentication bypass vulnerability exists in libcurl 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.

  ELA-831-1 curl security update