Amazon Linux 2023 : gnutls, gnutls-c++, gnutls-dane (ALAS2023-2025-1140)

high Nessus Plugin ID 251381

Synopsis

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

Description

It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2023-2025-1140 advisory.

A flaw was found in GnuTLS. A double-free vulnerability exists in GnuTLS due to incorrect ownership handling in the export logic of Subject Alternative Name (SAN) entries containing an otherName. If the type-id OID is invalid or malformed, GnuTLS will call asn1_delete_structure() on an ASN.1 node it does not own, leading to a double-free condition when the parent function or caller later attempts to free the same structure.

This vulnerability can be triggered using only public GnuTLS APIs and may result in denial of service or memory corruption, depending on allocator behavior. (CVE-2025-32988)

A heap-buffer-overread vulnerability was found in GnuTLS in how it handles the Certificate Transparency (CT) Signed Certificate Timestamp (SCT) extension during X.509 certificate parsing. This flaw allows a malicious user to create a certificate containing a malformed SCT extension (OID 1.3.6.1.4.1.11129.2.4.2) that contains sensitive data. This issue leads to the exposure of confidential information when GnuTLS verifies certificates from certain websites when the certificate (SCT) is not checked correctly.
(CVE-2025-32989)

A heap-buffer-overflow (off-by-one) flaw was found in the GnuTLS software in the template parsing logic within the certtool utility. When it reads certain settings from a template file, it allows an attacker to cause an out-of-bounds (OOB) NULL pointer write, resulting in memory corruption and a denial-of-service (DoS) that could potentially crash the system. (CVE-2025-32990)

A NULL pointer dereference flaw was found in the GnuTLS software in _gnutls_figure_common_ciphersuite().
When it reads certain settings from a template file, it can allow an attacker to cause an out-of-bounds (OOB) NULL pointer write, resulting in memory corruption and a denial of service (DoS) that could crash the system. (CVE-2025-6395)

Tenable has extracted the preceding description block directly from the tested product security advisory.

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 gnutls --releasever 2023.8.20250818' to update your system.

See Also

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

https://explore.alas.aws.amazon.com/CVE-2025-32988.html

https://explore.alas.aws.amazon.com/CVE-2025-32989.html

https://explore.alas.aws.amazon.com/CVE-2025-32990.html

https://explore.alas.aws.amazon.com/CVE-2025-6395.html

https://alas.aws.amazon.com//AL2023/ALAS2023-2025-1140.html

Plugin Details

Severity: High

ID: 251381

File Name: al2023_ALAS2023-2025-1140.nasl

Version: 1.1

Type: local

Agent: unix

Published: 8/18/2025

Updated: 8/18/2025

Supported Sensors: Continuous Assessment, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 5.0

CVSS v2

Risk Factor: High

Base Score: 8.5

Temporal Score: 6.3

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

CVSS Score Source: CVE-2025-32990

CVSS v3

Risk Factor: High

Base Score: 8.2

Temporal Score: 7.1

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

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

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:gnutls-c%2b%2b-debuginfo, p-cpe:/a:amazon:linux:gnutls-debuginfo, p-cpe:/a:amazon:linux:gnutls-debugsource, p-cpe:/a:amazon:linux:gnutls-utils, p-cpe:/a:amazon:linux:gnutls-utils-debuginfo, p-cpe:/a:amazon:linux:gnutls-dane-debuginfo, p-cpe:/a:amazon:linux:gnutls-devel, p-cpe:/a:amazon:linux:gnutls-dane, cpe:/o:amazon:linux:2023, p-cpe:/a:amazon:linux:gnutls, p-cpe:/a:amazon:linux:gnutls-c%2b%2b

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

Exploit Ease: No known exploits are available

Patch Publication Date: 8/18/2025

Vulnerability Publication Date: 6/10/2025

Reference Information

CVE: CVE-2025-32988, CVE-2025-32989, CVE-2025-32990, CVE-2025-6395