CVE-2019-15803
Zyxel GS1900 Unauthenticated Debug Access Control Bypass
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.
INFO
Published Date :
Nov. 14, 2019, 9:15 p.m.
Last Modified :
Aug. 24, 2020, 5:37 p.m.
Source :
[email protected]
Remotely Exploitable :
Yes !
Impact Score :
5.2
Exploitability Score :
3.9
Affected Products
The following products are affected by CVE-2019-15803
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2019-15803.
| URL | Resource |
|---|---|
| https://jasper.la/exploring-zyxel-gs1900-firmware-with-ghidra.html | Exploit Third Party Advisory |
| https://www.zyxel.com/support/gs1900-switch-vulnerabilities.shtml | Vendor Advisory |
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2019-15803 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2019-15803 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by [email protected]
May. 14, 2024
Action Type Old Value New Value -
CWE Remap by [email protected]
Aug. 24, 2020
Action Type Old Value New Value Changed CWE CWE-20 CWE-287 -
Initial Analysis by [email protected]
Nov. 21, 2019
Action Type Old Value New Value Added CVSS V2 NIST (AV:N/AC:L/Au:N/C:P/I:P/A:N) Added CVSS V3.1 NIST AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N Changed Reference Type https://jasper.la/exploring-zyxel-gs1900-firmware-with-ghidra.html No Types Assigned https://jasper.la/exploring-zyxel-gs1900-firmware-with-ghidra.html Exploit, Third Party Advisory Changed Reference Type https://www.zyxel.com/support/gs1900-switch-vulnerabilities.shtml No Types Assigned https://www.zyxel.com/support/gs1900-switch-vulnerabilities.shtml Vendor Advisory Added CWE NIST CWE-20 Added CPE Configuration AND OR *cpe:2.3:o:zyxel:gs1900-8_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 2.50\(aahh.0\)c0 OR cpe:2.3:h:zyxel:gs1900-8:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:zyxel:gs1900-8hp_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 2.50\(aahi.0\)c0 OR cpe:2.3:h:zyxel:gs1900-8hp:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:zyxel:gs1900-10hp_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 2.50\(aazi.0\)c0 OR cpe:2.3:h:zyxel:gs1900-10hp:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:zyxel:gs1900-16_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 2.50\(aahj.0\)c0 OR cpe:2.3:h:zyxel:gs1900-16:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:zyxel:gs1900-24e_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 2.50\(aahk.0\)c0 OR cpe:2.3:h:zyxel:gs1900-24e:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:zyxel:gs1900-24_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 2.50\(aahl.0\)c0 OR cpe:2.3:h:zyxel:gs1900-24:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:zyxel:gs1900-24hp_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 2.50\(aahm.0\)c0 OR cpe:2.3:h:zyxel:gs1900-24hp:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:zyxel:gs1900-48_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 2.50\(aahn.0\)c0 OR cpe:2.3:h:zyxel:gs1900-48:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:zyxel:gs1900-48hp_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 2.50\(aaho.0\)c0 OR cpe:2.3:h:zyxel:gs1900-48hp:-:*:*:*:*:*:*:*
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2019-15803 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2019-15803
weaknesses.
Exploit Prediction
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.
1.14 }} 0.30%
score
0.83128
percentile