CVE-2022-43389 — A buffer overflow vulnerability in the library of the web server in Zyxel NR7101

A buffer overflow vulnerability in the library of the web server in Zyxel NR7101 firmware prior to V1.15(ACCC.3)C0, which could allow an unauthenticated attacker to execute some OS commands or to cause denial-of-service (DoS) conditions on a vulnerable device.

01What is this vulnerability?

A buffer overflow vulnerability in the library of the web server in Zyxel NR7101 firmware prior to V1.15(ACCC.3)C0, which could allow an unauthenticated attacker to execute some OS commands or to cause denial-of-service (DoS) conditions on a vulnerable device.

02Affected products

Vendor	Product	Versions
Zyxel	NR7101 firmware	< V1.15(ACCC.3)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: 2025-04-09T13:52:22.737Z

09References

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