An inaccurate frame deduplication process in ChirpStack Network Server 3.9.0 allows a malicious gateway to perform uplink Denial of Service via malformed frequency attributes in CollectAndCallOnceCollect in internal/uplink/collect.go. NOTE: the vendor's position is that there are no "guarantees that allowing untrusted LoRa gateways to the network should still result in a secure network.
Conclusion & alert: CVE-2020-28349 is rated High Exploit Risk (70.8/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 2.17%). Core evidence: 1 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +1.79% over the last day, indicating growing attacker interest. Mandatory action: Public exploits are available—assess exposure, apply mitigations, and prioritize patching.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
| EDB-ID | Source | Kind | Published | Link |
|---|---|---|---|---|
| — | nvd_ref | exploit_tag | Exploit-DB ↗ |
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-15 | 0.39% | 2.17% | +1.79% |
| 2 | 2026-04-01 | 0.50% | 0.39% | -0.11% |
| 3 | 2025-11-21 | — | 0.50% | — |
Full EPSS history (14 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 6.5 | 3.1 | MEDIUM |
|
2.8 | 3.6 | [email protected] |
| 6.8 | 2.0 | MEDIUM |
|
8.0 | 6.9 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| chirpstack | network_server | 3.9.0 | cpe:2.3:a:chirpstack:network_server:3.9.0:*:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://github.com/brocaar/chirpstack-network-server/commit/874fc1a9b01045ebe8a340f0bb01ed19e8256e60 | Patch Third Party Advisory |
| https://github.com/brocaar/chirpstack-network-server/commit/f996bb0c6c85281b5658f59ff09db1b4a73db453 | Patch Third Party Advisory |
| https://www.cyberark.com/resources/threat-research-blog/lorawan-mqtt-what-to-know-when-securing-your-iot-network | Exploit Third Party Advisory |