Amazon Linux 2023 : libssh, libssh-config, libssh-devel (ALAS2023-2025-1264)

medium Nessus Plugin ID 274674

Synopsis

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

Description

It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2023-2025-1264 advisory.

NULL Pointer Dereference vulnerability in the session ID calculation logic of the libssh library. The flaw arises from improper handling of allocation errors during cryptographic operations in the key exchange (KEX) phase. If a memory allocation fails, the resulting NULL pointer may be dereferenced, leading to a crash in both SSH clients and servers. This vulnerability can be exploited by a local attacker with limited privileges and no user interaction, potentially disrupting services that rely on libssh for secure communication.The issue affects libssh versions up to and including 0.11.2. (CVE-2025-8114)

A flaw was found in libssh's handling of key exchange (KEX) processes when a client repeatedly sends incorrect KEX guesses. The library fails to free memory during these rekey operations, which can gradually exhaust system memory. This issue can lead to crashes on the client side, particularly when using libgcrypt, which impacts application stability and availability. (CVE-2025-8277)

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 libssh --releasever 2023.9.20251110' or or 'dnf update --advisory ALAS2023-2025-1264 --releasever 2023.9.20251110' to update your system.

Plugin Details

Severity: Medium

ID: 274674

File Name: al2023_ALAS2023-2025-1264.nasl

Version: 1.1

Type: local

Agent: unix

Family: Amazon Linux Local Security Checks

Published: 11/11/2025

Updated: 11/11/2025

Supported Sensors: Nessus Agent, Continuous Assessment, Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3.6

CVSS v2

Risk Factor: Low

Base Score: 3.8

Temporal Score: 2.8

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

CVSS Score Source: CVE-2025-8114

CVSS v3

Risk Factor: Medium

Base Score: 4.7

Temporal Score: 4.1

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

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

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:libssh-config, p-cpe:/a:amazon:linux:libssh-devel, p-cpe:/a:amazon:linux:libssh-debuginfo, p-cpe:/a:amazon:linux:libssh-debugsource, p-cpe:/a:amazon:linux:libssh, cpe:/o:amazon:linux:2023

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

Exploit Ease: No known exploits are available

Patch Publication Date: 11/10/2025

Vulnerability Publication Date: 7/24/2025

Reference Information

CVE: CVE-2025-8114, CVE-2025-8277

IAVA: 2025-A-0692

Detections

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