Vulnerability identifier: #VU49149
Vulnerability risk: Critical
CVSSv3.1: 9.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H/E:H/RL:O/RC:C]
CVE-ID:
CWE-ID:
CWE-798
Exploitation vector: Network
Exploit availability: Yes
Vulnerable software:
NXC2500
Hardware solutions /
Routers & switches, VoIP, GSM, etc
NXC5500
Hardware solutions /
Routers & switches, VoIP, GSM, etc
ZyXEL ZLD
Hardware solutions /
Firmware
Vendor: ZyXEL Communications Corp.
Description
The vulnerability allows a remote attacker to gain full access to vulnerable system.
The vulnerability exists due to presence of hard-coded account zyfwp with an unchangeable password. A remote unauthenticated attacker can access the affected system via ssh or web interface using the hard-coded credentials and gain administrative privileges.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
Mitigation
Install updates from vendor's website.
Vulnerable software versions
NXC2500: All versions
NXC5500: All versions
ZyXEL ZLD: 4.60
External links
http://ftp.zyxel.com/USG40/firmware/USG40_4.60(AALA.1)C0_2.pdf
http://businessforum.zyxel.com/discussion/5252/zld-v4-60-revoke-and-wk48-firmware-release
http://businessforum.zyxel.com/discussion/5254/whats-new-for-zld4-60-patch-1-available-on-dec-15
http://www.eyecontrol.nl/blog/undocumented-user-account-in-zyxel-products.html
http://www.zyxel.com/support/CVE-2020-29583.shtml
http://www.zyxel.com/support/security_advisories.shtml
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?
Yes. This vulnerability is being exploited in the wild.