CVE-2020-9054 Zyxel Multiple NAS Devices OS Command Injection
Remote unauthenticated attackers can execute arbitrary code with root privileges on ZyXEL NAS devices via command injection in weblogin.cgi.
- Exploited in the wild
- Since 25 Mar 2022
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2020-9054?
CVE-2020-9054 is a critical command injection vulnerability in ZyXEL NAS326, published on 4 Mar 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Multiple ZyXEL network-attached storage (NAS) devices running firmware version 5.21 contain a pre-authentication command injection vulnerability, which may allow a remote, unauthenticated attacker to execute arbitrary code on a vulnerable device. ZyXEL NAS devices achieve authentication by using the weblogin.cgi CGI executable. This program fails to properly sanitize the username parameter that is passed to it. If the username parameter contains certain characters, it can allow command injection with the privileges of the web server that runs on the ZyXEL device. Although the web server does not run as the root user, ZyXEL devices include a setuid utility that can be leveraged to run any command with root privileges. As such, it should be assumed that exploitation of this vulnerability can lead to remote code execution with root privileges. By sending a specially-crafted HTTP POST or GET request to a vulnerable ZyXEL device, a remote, unauthenticated attacker may be able to execute arbitrary code on the device. This may happen by directly connecting to a device if it is directly exposed to an attacker. However, there are ways to trigger such crafted requests even if an attacker does not have direct connectivity to a vulnerable devices. For example, simply visiting a website can result in the compromise of any ZyXEL device that is reachable from the client system. Affected products include: NAS326 before firmware V5.21(AAZF.7)C0 NAS520 before firmware V5.21(AASZ.3)C0 NAS540 before firmware V5.21(AATB.4)C0 NAS542 before firmware V5.21(ABAG.4)C0 ZyXEL has made firmware updates available for NAS326, NAS520, NAS540, and NAS542 devices. Affected models that are end-of-support: NSA210, NSA220, NSA220+, NSA221, NSA310, NSA310S, NSA320, NSA320S, NSA325 and NSA325v2
Weakness: CWE-78
Which versions are affected by CVE-2020-9054?
It affects 27 products.
Products include Zyxel Atp100 Firmware, Zyxel Atp200 Firmware, Zyxel Atp500 Firmware, Zyxel Atp800 Firmware, Zyxel Nas326 Firmware, Zyxel Nas520 Firmware and 21 more.
How do I fix CVE-2020-9054?
No fix has been published for CVE-2020-9054 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 15 Apr 2022.
Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.
Is CVE-2020-9054 being exploited?
Yes. Attackers have exploited CVE-2020-9054 in the wild since at least 25 Mar 2022.
Public exploit code: 1 Nuclei template and 1 proofs of concept on GitHub.
Other vulnerabilities in ZyXEL NAS326
- CVE-2023-33009 Zyxel Multiple Firewalls Buffer Overflow
- CVE-2023-33010 Zyxel Multiple Firewalls Buffer Overflow
- CVE-2023-28771 Zyxel Multiple Firewalls OS Command Injection
- CVE-2022-30525 Zyxel Multiple Firewalls OS Command Injection
- CVE-2020-29583 Zyxel Multiple Products Use of Hard-Coded Credentials
Sources
Also known as GHSA-w6h5-rjp3-hxvc.