Amazon Linux AMI update for zsh

1) OS Command Injection

EUVDB-ID: #VU60674

Risk: High

CVSSv4.0: 5.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2021-45444

CWE-ID: CWE-78 - Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

Exploit availability: No

Description

The vulnerability allows a remote attacker to execute arbitrary shell commands on the target system.

The vulnerability exists due to recursive PROMPT_SUBST expansion when processing malicious output. A remote attacker with ability to control the output can inject and execute arbitrary commands on the system with privileges on the current user.

Mitigation

Update the affected packages:

aarch64:
    zsh-debugsource-5.8.1-1.amzn2023.0.3.aarch64
    zsh-debuginfo-5.8.1-1.amzn2023.0.3.aarch64
    zsh-5.8.1-1.amzn2023.0.3.aarch64

noarch:
    zsh-html-5.8.1-1.amzn2023.0.3.noarch

src:
    zsh-5.8.1-1.amzn2023.0.3.src

x86_64:
    zsh-debugsource-5.8.1-1.amzn2023.0.3.x86_64
    zsh-debuginfo-5.8.1-1.amzn2023.0.3.x86_64
    zsh-5.8.1-1.amzn2023.0.3.x86_64

Vulnerable software versions

Amazon Linux AMI: All versions

zsh: All versions

CPE2.3

• cpe:2.3:o:amazon_web_services:amazon_linux_ami:*:*:*:*:*:*:*:*
• cpe:2.3:a:amazon_web_services:zsh:*:*:*:*:*:amazon_linux_ami:*:*

External links

https://alas.aws.amazon.com/AL2023/ALAS-2023-035.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.