Amazon Linux 2 : samba (ALAS-2023-2367)

medium Nessus Plugin ID 186552

Synopsis

The remote Amazon Linux 2 host is missing a security update.

Description

The version of samba installed on the remote host is prior to 4.10.16-24. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2023-2367 advisory.

- An out-of-bounds read vulnerability was found in Samba due to insufficient length checks in winbindd_pam_auth_crap.c. When performing NTLM authentication, the client replies to cryptographic challenges back to the server. These replies have variable lengths, and Winbind fails to check the lan manager response length. When Winbind is used for NTLM authentication, a maliciously crafted request can trigger an out-of-bounds read in Winbind, possibly resulting in a crash. (CVE-2022-2127)

- A vulnerability was discovered in Samba, where the flaw allows SMB clients to truncate files, even with read-only permissions when the Samba VFS module acl_xattr is configured with acl_xattr:ignore system acls = yes. The SMB protocol allows opening files when the client requests read-only access but then implicitly truncates the opened file to 0 bytes if the client specifies a separate OVERWRITE create disposition request. The issue arises in configurations that bypass kernel file system permissions checks, relying solely on Samba's permissions. (CVE-2023-4091)

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

Solution

Run 'yum update samba' to update your system.

See Also

https://alas.aws.amazon.com/AL2/ALAS-2023-2367.html

https://alas.aws.amazon.com/cve/html/CVE-2022-2127.html

https://alas.aws.amazon.com/cve/html/CVE-2023-4091.html

https://alas.aws.amazon.com/faqs.html

Plugin Details

Severity: Medium

ID: 186552

File Name: al2_ALAS-2023-2367.nasl

Version: 1.0

Type: local

Agent: unix

Published: 12/4/2023

Updated: 12/4/2023

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

Risk Information

VPR

Risk Factor: Medium

Score: 4.4

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5

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

CVSS Score Source: CVE-2023-4091

CVSS v3

Risk Factor: Medium

Base Score: 6.5

Temporal Score: 5.7

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

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

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:samba-winbind-krb5-locator, p-cpe:/a:amazon:linux:libwbclient, p-cpe:/a:amazon:linux:samba-common-tools, cpe:/o:amazon:linux:2, p-cpe:/a:amazon:linux:samba-python-test, p-cpe:/a:amazon:linux:samba, p-cpe:/a:amazon:linux:samba-client-libs, p-cpe:/a:amazon:linux:samba-client, p-cpe:/a:amazon:linux:samba-python, p-cpe:/a:amazon:linux:samba-test, p-cpe:/a:amazon:linux:samba-common-libs, p-cpe:/a:amazon:linux:samba-dc-libs, p-cpe:/a:amazon:linux:samba-debuginfo, p-cpe:/a:amazon:linux:samba-winbind, p-cpe:/a:amazon:linux:samba-krb5-printing, p-cpe:/a:amazon:linux:samba-vfs-glusterfs, p-cpe:/a:amazon:linux:libsmbclient-devel, p-cpe:/a:amazon:linux:samba-devel, p-cpe:/a:amazon:linux:samba-common, p-cpe:/a:amazon:linux:samba-dc, p-cpe:/a:amazon:linux:samba-libs, p-cpe:/a:amazon:linux:samba-pidl, p-cpe:/a:amazon:linux:samba-winbind-clients, p-cpe:/a:amazon:linux:ctdb-tests, p-cpe:/a:amazon:linux:libwbclient-devel, p-cpe:/a:amazon:linux:libsmbclient, p-cpe:/a:amazon:linux:samba-winbind-modules, p-cpe:/a:amazon:linux:ctdb, p-cpe:/a:amazon:linux:samba-test-libs

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

Exploit Ease: No known exploits are available

Patch Publication Date: 11/29/2023

Vulnerability Publication Date: 7/20/2023

Reference Information

CVE: CVE-2022-2127, CVE-2023-4091

IAVA: 2023-A-0376-S, 2023-A-0535