CVE-2023-31130: Buffer Underwrite in ares_inet_net_pton()

Overview

Severity

Medium (CVSS 6.4)

CVSS Vector

CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H

Exploit Status

Not Exploited

Patch Tuesday

2023-May

Released

2023-05-30

Last Updated

2026-10-21

EPSS Score

0.38% (percentile: 32.3%)

FAQ

Is Azure Linux the only Microsoft product that includes this open-source library and is therefore potentially affected by this vulnerability? One of the main benefits to our customers who choose to use the Azure Linux distro is the commitment to keep it up to date with the most recent and most secure versions of the open source libraries with which the distro is composed. Microsoft is committed to transparency in this work which is why we began publishing CSAF/VEX in October 2025. See this blog post for more information. If impact to additional products is identified, we will update the CVE to reflect this.

Affected Products (9)

Mariner

• cm1 c-ares 1.19.1-1 on CBL Mariner 1.0
• cbl2 python-gevent 21.1.2-3 on CBL Mariner 2.0
• cbl2 nodejs18 18.17.1-2 on CBL Mariner 2.0
• cbl2 nodejs 16.20.1-2 on CBL Mariner 2.0
• cbl2 grpc 1.42.0-11 on CBL Mariner 2.0
• cbl2 fluent-bit 2.1.10-1 on CBL Mariner 2.0
• cbl2 c-ares 1.19.1-1 on CBL Mariner 2.0
• azl3 grpc 1.62.0-2 on Azure Linux 3.0

Open Source Software

• azl3 grpc 1.42.0-7 on Azure Linux 3.0

Revision History

• 2023-05-30: Information published.
• 2023-05-31: Added nodejs to CBL-Mariner 2.0
• 2024-06-30: Information published.
• 2025-04-08: Added grpc to CBL-Mariner 2.0 Added fluent-bit to CBL-Mariner 2.0 Added nodejs18 to CBL-Mariner 2.0 Added nodejs to CBL-Mariner 2.0 Added c-ares to CBL-Mariner 2.0 Added grpc to Azure Linux 3.0 Added c-ares to CBL-Mariner 1.0
• 2026-02-18: Information published.
• 2026-08-12: Information published.
• 2026-10-21: Information published.