Zero-day vulnerability in acme.sh

OS Command Injection
CVE-2023-38198

The vulnerability was exploited through the Chinese intermediary HiCA who claims to be compromised.

Vulnerability details

Advisory: SB2023062017 - Remote code execution in acme.sh

Vulnerable component: acme.sh

CVE-ID: CVE-2023-38198

CVSSv3 score: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:H/RL:O/RC:C

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

Description:

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

The vulnerability exists due to improper input validation when parsing certificates. A remote attacker can pass specially crafted data to the application and execute arbitrary OS commands on the target system.

Note, exploitation of this vulnerability has been observed in the wild by compromised HiCA servers.

External links:

https://twitter.com/aleksejspopovs/status/1666955050696966148

https://groups.google.com/a/mozilla.org/g/dev-security-policy/c/heXVr8o83Ys

https://github.com/acmesh-official/acme.sh/issues/4659

About zero-day vulnerabilities

Zero-day vulnerability is an undisclosed vulnerability in software that hackers can exploit to compromise computer programs, gain unauthorized access to sensitive data, penetrate networks, etc. We consider vulnerability a zero-day when there is no solution provided from software vendor and the vulnerability is being actively exploited by malicious actors.

Zero-day candidate is a potential zero-day vulnerability in software which might have been used in targeted attacks, however there is no evidence to support this suggestion.