CVE-2024-38270 — An insufficient entropy vulnerability caused by the improper use of a randomness

An insufficient entropy vulnerability caused by the improper use of a randomness function with low entropy for web authentication tokens generation exists in the Zyxel GS1900-10HP firmware version V2.80(AAZI.0)C0. This vulnerability could allow a LAN-based attacker a slight chanc

01What is this vulnerability?

An insufficient entropy vulnerability caused by the improper use of a randomness function with low entropy for web authentication tokens generation exists in the Zyxel GS1900-10HP firmware version V2.80(AAZI.0)C0. This vulnerability could allow a LAN-based attacker a slight chance to gain a valid session token if multiple authenticated sessions are alive.

02Affected products

Vendor	Product	Versions
Zyxel	GS1900	10HP firmware — V2.80(AAZI.0)C0

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Open the Sigma generator with a pre-filled prompt for this CVE to draft a starting detection in your stack of choice:

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07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2024-09-10T01:20:09.147Z
• Last modified: 2024-09-10T15:15:34.477Z

09References

• www.zyxel.com — https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advis…