Detections
Analytics

Amazon Linux 2 : ant (ALAS-2026-4020)

high Nessus Plugin ID 371778

Synopsis

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

Description

The version of ant installed on the remote host is prior to 1.9.16-1. It is, therefore, affected by a vulnerability as referenced in the ALAS2-2026-4020 advisory.

 The ftp and scp tasks of Apache Ant can download files from a remote server. A malicious server can provide relative paths that allow it to write outside of the dedicated target directory for the download, making it possible to overwrite files of the attacker's choice using the permissions of the user running Ant in versions prior to Ant 1.10.18.



 In order to exploit this vulnerability, the server would either have to be malicious or be subject to a machine-in-the-middle attack. Additionally in the case of scp or the ftp task using ftps the server must pass the server identity checks performed by the tasks.



 For ftp tasks not using ftps a malicious server could act as a machine-in-the-middle to provide malicious files.



 Starting with Ant 1.10.18 both tasks will prevent writing outside of the destination directory by default.
 An option is available to disable this behavior in the unlikely case that the old behavior is required by existing build files.



 Mitigations:



 Users of scp and ftp (when using ftps) in any version of Ant should not bypass server identity checks.
 Users of ftp not using ftps should switch to ftps where possible.



 All users are recommended to upgrade to Apache Ant 1.10.18, which fixes this issue. (CVE-2026-78254)

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

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

Solution

Run 'yum update ant' or or 'yum update --advisory ALAS2-2026-4020' to update your system.

See Also

https://alas.aws.amazon.com//AL2/ALAS2-2026-4020.html

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

https://explore.alas.aws.amazon.com/CVE-2026-78254.html

Plugin Details

Severity: High

ID: 371778

File Name: al2_ALAS-2026-4020.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 10/24/2026

Updated: 10/24/2026

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Continuous Assessment, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.3

Percentile: 53.48

CVSS v2

Risk Factor: High

Base Score: 7.6

Temporal Score: 5.6

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

CVSS Score Source: CVE-2026-78254

CVSS v3

Risk Factor: High

Base Score: 7.4

Temporal Score: 6.4

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

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

Vulnerability Information

CPE: cpe:/o:amazon:linux:2, p-cpe:/a:amazon:linux:ant-antlr, p-cpe:/a:amazon:linux:ant-apache-bcel, p-cpe:/a:amazon:linux:ant-apache-bsf, p-cpe:/a:amazon:linux:ant-apache-log4j, p-cpe:/a:amazon:linux:ant-apache-oro, p-cpe:/a:amazon:linux:ant-apache-regexp, p-cpe:/a:amazon:linux:ant-apache-resolver, p-cpe:/a:amazon:linux:ant-apache-xalan2, p-cpe:/a:amazon:linux:ant-commons-logging, p-cpe:/a:amazon:linux:ant-commons-net, p-cpe:/a:amazon:linux:ant-javadoc, p-cpe:/a:amazon:linux:ant-javamail, p-cpe:/a:amazon:linux:ant-jdepend, p-cpe:/a:amazon:linux:ant-jmf, p-cpe:/a:amazon:linux:ant-jsch, p-cpe:/a:amazon:linux:ant-junit, p-cpe:/a:amazon:linux:ant-manual, p-cpe:/a:amazon:linux:ant-swing, p-cpe:/a:amazon:linux:ant-testutil, p-cpe:/a:amazon:linux:ant

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

Exploit Ease: No known exploits are available

Patch Publication Date: 10/24/2026

Vulnerability Publication Date: 9/7/2026

Reference Information

CVE: CVE-2026-78254