An insufficient entropy vulnerability caused by the improper use of randomness sources with low entropy for RSA key pair generation was found in Zyxel GS1900 series firmware versions prior to V2.70. This vulnerability could allow an unauthenticated attacker to retrieve a private key by factoring the RSA modulus N in the certificate of the web administration interface.

References

• https://nvd.nist.gov/vuln/detail/CVE-2022-34746
• https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-insufficient-entropy-vulnerability-of-gs1900-series-switches