CVE-2022-43393 — An improper check for unusual or exceptional conditions in the HTTP request proc

An improper check for unusual or exceptional conditions in the HTTP request processing function of Zyxel GS1920-24v2 firmware prior to V4.70(ABMH.8)C0, which could allow an unauthenticated attacker to corrupt the contents of the memory and result in a denial-of-service (DoS) cond

01What is this vulnerability?

An improper check for unusual or exceptional conditions in the HTTP request processing function of Zyxel GS1920-24v2 firmware prior to V4.70(ABMH.8)C0, which could allow an unauthenticated attacker to corrupt the contents of the memory and result in a denial-of-service (DoS) condition on a vulnerable device.

02Affected products

Vendor	Product	Versions
Zyxel	GS1920	24v2 firmware — < V4.70(ABMH.8)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

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

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: 2023-01-11T00:00:00.000Z
• Last modified: 2025-04-08T14:29:52.874Z

09References

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