FKIE_CVE-2019-15803
Vulnerability from fkie_nvd - Published: 2019-11-14 21:15 - Updated: 2026-06-17 02:21
Severity
Summary
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.
References
| URL | Tags | ||
|---|---|---|---|
| cve@mitre.org | https://jasper.la/exploring-zyxel-gs1900-firmware-with-ghidra.html | Exploit, Third Party Advisory | |
| cve@mitre.org | https://www.zyxel.com/support/gs1900-switch-vulnerabilities.shtml | Vendor Advisory | |
| af854a3a-2127-422b-91ae-364da2661108 | https://jasper.la/exploring-zyxel-gs1900-firmware-with-ghidra.html | Exploit, Third Party Advisory | |
| af854a3a-2127-422b-91ae-364da2661108 | https://www.zyxel.com/support/gs1900-switch-vulnerabilities.shtml | Vendor Advisory |
Impacted products
| Vendor | Product | Version | |
|---|---|---|---|
| zyxel | gs1900-8_firmware | * | |
| zyxel | gs1900-8 | - | |
| zyxel | gs1900-8hp_firmware | * | |
| zyxel | gs1900-8hp | - | |
| zyxel | gs1900-10hp_firmware | * | |
| zyxel | gs1900-10hp | - | |
| zyxel | gs1900-16_firmware | * | |
| zyxel | gs1900-16 | - | |
| zyxel | gs1900-24e_firmware | * | |
| zyxel | gs1900-24e | - | |
| zyxel | gs1900-24_firmware | * | |
| zyxel | gs1900-24 | - | |
| zyxel | gs1900-24hp_firmware | * | |
| zyxel | gs1900-24hp | - | |
| zyxel | gs1900-48_firmware | * | |
| zyxel | gs1900-48 | - | |
| zyxel | gs1900-48hp_firmware | * | |
| zyxel | gs1900-48hp | - |
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"lastModified": "2026-06-17T02:21:06.443",
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
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