Amazon Linux 2023 : curl, curl-minimal, libcurl (ALAS2023-2023-193)

high Nessus Plugin ID 176898

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Synopsis

The remote Amazon Linux 2023 host is missing a security update.

Description

It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2023-2023-193 advisory.

- A vulnerability in input validation exists in curl <8.0 during communication using the TELNET protocol 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-2023-27533)

- A path traversal vulnerability exists in curl <8.0.0 SFTP implementation causes the tilde (~) character to be wrongly replaced when used as a prefix in the first path element, in addition to its intended use as the first element to indicate a path relative to the user's home directory. Attackers can exploit this flaw to bypass filtering or execute arbitrary code by crafting a path like /~2/foo while accessing a server with a specific user. (CVE-2023-27534)

- 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. (CVE-2023-27535)

- An authentication bypass vulnerability exists libcurl <8.0.0 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-2023-27536)

- A double free vulnerability exists in libcurl <8.0.0 when sharing HSTS data between separate handles.
This sharing was introduced without considerations for do this sharing across separate threads but there was no indication of this fact in the documentation. Due to missing mutexes or thread locks, two threads sharing the same HSTS data could end up doing a double-free or use-after-free. (CVE-2023-27537)

- An authentication bypass vulnerability exists in libcurl prior to 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. (CVE-2023-27538)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Run 'dnf update curl --releasever 2023.0.20230607' to update your system.

Plugin Details

Severity: High

ID: 176898

File Name: al2023_ALAS2023-2023-193.nasl

Version: 1.1

Type: local

Agent: unix

Family: Amazon Linux Local Security Checks

Published: 6/8/2023

Updated: 6/8/2023

Supported Sensors: Agentless Assessment, Continuous Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

CVSS Score Source: CVE-2023-27533

CVSS v3

Risk Factor: High

Base Score: 8.8

Temporal Score: 7.9

Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

CVSS Score Source: CVE-2023-27534

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:libcurl, p-cpe:/a:amazon:linux:libcurl-devel, p-cpe:/a:amazon:linux:curl-debuginfo, p-cpe:/a:amazon:linux:curl-debugsource, p-cpe:/a:amazon:linux:curl-minimal, p-cpe:/a:amazon:linux:curl-minimal-debuginfo, p-cpe:/a:amazon:linux:libcurl-debuginfo, p-cpe:/a:amazon:linux:libcurl-minimal-debuginfo, p-cpe:/a:amazon:linux:libcurl-minimal, p-cpe:/a:amazon:linux:curl, cpe:/o:amazon:linux:2023

Required KB Items: Host/local_checks_enabled, Host/AmazonLinux/release, Host/AmazonLinux/rpm-list

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 6/5/2023

Vulnerability Publication Date: 3/20/2023

Reference Information

CVE: CVE-2023-27533, CVE-2023-27534, CVE-2023-27535, CVE-2023-27536, CVE-2023-27537, CVE-2023-27538

IAVA: 2023-A-0153-S

Detections

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