CVE-2022-34746Network attack vector

TLS private-key recovery via low-entropy RSA generation

Published Sep 20, 2022 · Updated May 29, 2025

Insufficient entropy in Zyxel GS1900 Series Firmware before V2.70 allows remote attackers to recover the web interface TLS private key. The RSA key-pair generator draws from low-entropy randomness, producing a factorable modulus N in the web administration certificate. No authentication is required; possession of the recovered key permits decryption of captured TLS traffic or impersonation of the switch's certificate owner.

CVSS severity5.9
Medium
EPSS probability0.34%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Insufficient entropy in Zyxel GS1900 Series Firmware before V2.70 allows remote attackers to recover the web interface TLS private key. The RSA key-pair generator draws from low-entropy randomness, producing a factorable modulus N in the web administration certificate. No authentication is required; possession of the recovered key permits decryption of captured TLS traffic or impersonation of the switch's certificate owner.

The record

CVE
CVE-2022-34746
Published
Sep 20, 2022
Updated
May 29, 2025
Vendor
Zyxel Networks
Product
GS1900 Series Firmware
Classifications
CWE-331, T1557
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 20, 2022CVE publishedPublication date reported by the CVE source.
  2. May 29, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< V2.70

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Zyxel Networks · GS1900 Series Firmwareversion=< V2.70

Published CVSS scores

5.9Zyxel CorporationCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-331Insufficient Entropy
T1557Adversary-in-the-Middle

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo