Buffer Overflow in Asuswrt Merlin Project (CVE-2017-11420, CVSS 9.8)

Summary

Vulnerability in Asuswrt Merlin Project (CVE-2017-11420). Successful exploitation can lead to full system takeover.

Original description

The description as published by the source.

Stack-based buffer overflow in ASUS_Discovery.c in networkmap in Asuswrt-Merlin firmware for ASUS devices and ASUS firmware for ASUS RT-AC5300, RT_AC1900P, RT-AC68U, RT-AC68P, RT-AC88U, RT-AC66U, RT-AC66U_B1, RT-AC58U, RT-AC56U, RT-AC55U, RT-AC52U, RT-AC51U, RT-N18U, RT-N66U, RT-N56U, RT-AC3200, RT-AC3100, RT_AC1200GU, RT_AC1200G, RT-AC1200, RT-AC53, RT-N12HP, RT-N12HP_B1, RT-N12D1, RT-N12+, RT_N12+_PRO, RT-N16, and RT-N300 devices allows remote attackers to execute arbitrary code via long device information that is mishandled during a strcat to a device list.

Source: NIST National Vulnerability Database NVD

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as CVE-2017-11420 has been found in Asuswrt Merlin Project.
Successful exploitation can lead to full system takeover. CVSS score: 9.8/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Asuswrt Merlin Project CVE-2017-11420" on the vendor's site.

CVE-2017-11420 (Asuswrt Merlin Project) — CWE-119 / CVSS v3 9.8
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

A vulnerability (CWE-119) exists in Asuswrt Merlin Project.

📍 Affected scope

Check the vendor advisory for the affected versions of Asuswrt Merlin Project.

🔥 Severity

Severity: Critical (CVSS 9.8/10). Successful exploitation can lead to full system takeover.

🔧 How to fix

Update to the patched release per vendor advisory.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

1
Identify exposure identify
```
Audit SBOM/dependencies for affected components.
```
資産台帳・SBOM・依存マニフェストで Asuswrt Merlin Project を使っているサービスとバージョンを洗い出す。
2
Post-deployment verification verify
```
Confirm patched version is live in production
```
パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。

References

exploit openwall.com
web asuswrt.lostrealm.ca