Amazon Linux AMI update for unbound

Published: 2024-08-06 | Updated: 2024-08-23

Risk	Medium
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2023-50387 CVE-2023-50868
CWE-ID	CWE-400
Exploitation vector	Network
Public exploit	Public exploit code for vulnerability #1 is available. Public exploit code for vulnerability #2 is available.
Vulnerable software	Amazon Linux AMI Operating systems & Components / Operating system unbound Operating systems & Components / Operating system package or component
Vendor	Amazon Web Services

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Resource exhaustion

EUVDB-ID: #VU86377

Risk: Medium

CVSSv4.0: 7.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P/U:Green]

CVE-ID: CVE-2023-50387

CWE-ID: CWE-400 - Resource exhaustion

Exploit availability: Yes

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to improper input validation when processing DNSSEC related records. A remote attacker can trigger resource exhaustion by forcing the DNS server to query a specially crafted DNSSEC zone and perform a denial of service (DoS) attack.

Mitigation

Update the affected packages:

aarch64:
    unbound-libs-debuginfo-1.17.1-1.amzn2023.0.2.aarch64
    unbound-debuginfo-1.17.1-1.amzn2023.0.2.aarch64
    python3-unbound-1.17.1-1.amzn2023.0.2.aarch64
    unbound-libs-1.17.1-1.amzn2023.0.2.aarch64
    unbound-anchor-debuginfo-1.17.1-1.amzn2023.0.2.aarch64
    unbound-debugsource-1.17.1-1.amzn2023.0.2.aarch64
    unbound-utils-1.17.1-1.amzn2023.0.2.aarch64
    unbound-utils-debuginfo-1.17.1-1.amzn2023.0.2.aarch64
    unbound-anchor-1.17.1-1.amzn2023.0.2.aarch64
    unbound-devel-1.17.1-1.amzn2023.0.2.aarch64
    python3-unbound-debuginfo-1.17.1-1.amzn2023.0.2.aarch64
    unbound-1.17.1-1.amzn2023.0.2.aarch64

src:
    unbound-1.17.1-1.amzn2023.0.2.src

x86_64:
    unbound-debuginfo-1.17.1-1.amzn2023.0.2.x86_64
    unbound-utils-1.17.1-1.amzn2023.0.2.x86_64
    unbound-utils-debuginfo-1.17.1-1.amzn2023.0.2.x86_64
    unbound-libs-debuginfo-1.17.1-1.amzn2023.0.2.x86_64
    python3-unbound-1.17.1-1.amzn2023.0.2.x86_64
    unbound-1.17.1-1.amzn2023.0.2.x86_64
    unbound-anchor-debuginfo-1.17.1-1.amzn2023.0.2.x86_64
    python3-unbound-debuginfo-1.17.1-1.amzn2023.0.2.x86_64
    unbound-debugsource-1.17.1-1.amzn2023.0.2.x86_64
    unbound-anchor-1.17.1-1.amzn2023.0.2.x86_64
    unbound-libs-1.17.1-1.amzn2023.0.2.x86_64
    unbound-devel-1.17.1-1.amzn2023.0.2.x86_64

Vulnerable software versions

Amazon Linux AMI: All versions

unbound: All versions

CPE2.3

External links

https://alas.aws.amazon.com/AL2023/ALAS-2024-553.html

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.

2) Resource exhaustion

EUVDB-ID: #VU86378