CVE-2019-15803 Auth bypass in n/a
Attackers can bypass authentication to access a diagnostics shell on Zyxel switches, allowing arbitrary register access and configuration changes.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2019-15803?
CVE-2019-15803 is a critical authentication bypass vulnerability in n/a, published on 14 Nov 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
An issue was discovered on Zyxel GS1900 devices with firmware before 2.50(AAHH.0)C0. Through an undocumented sequence of keypresses, undocumented functionality is triggered. A diagnostics shell is triggered via CTRL-ALT-t, which prompts for the password returned by fds_sys_passDebugPasswd_ret(). The firmware contains access control checks that determine if remote users are allowed to access this functionality. The function that performs this check (fds_sys_remoteDebugEnable_ret in libfds.so) always return TRUE with no actual checks performed. The diagnostics menu allows for reading/writing arbitrary registers and various other configuration parameters which are believed to be related to the network interface chips.
Weakness: CWE-287
Which versions are affected by CVE-2019-15803?
It affects 9 products.
Products include Zyxel Gs1900-10hp Firmware, Zyxel Gs1900-16 Firmware, Zyxel Gs1900-24 Firmware, Zyxel Gs1900-24e Firmware, Zyxel Gs1900-24hp Firmware, Zyxel Gs1900-48 Firmware and 3 more.
How do I fix CVE-2019-15803?
No fix has been published for CVE-2019-15803 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2019-15803 being exploited?
There is no known exploitation of CVE-2019-15803 in the wild and no public exploit code.
Other vulnerabilities in n/a
Sources
Also known as GHSA-958f-78j2-fqr6.