basicsecurity.net
Proof, not just disclosure.
Threats / Zyxel / CVE-2017-18368
CVE-2017-18368 · EUVD no mirror located · GCVE no mirror located Verified 2026-06-22

Zyxel P660HN-T1A Routers vulnerability

Zyxel P660HN-T1A routers are vulnerable to unauthenticated command injection via the Remote System Log forwarding function. The remote_host parameter in ViewLog.asp does not properly sanitize input, allowing attackers to execute arbitrary c

Verdict

Today item — known-exploited.

An unauthenticated remote attacker can inject and execute arbitrary system commands on affected Zyxel routers through the ViewLog.asp interface, potentially leading to full device compromise, network access, or lateral movement into connected networks.

CISA KEV Yes · 2023-08-073EPSS 0.94508 (verify live)4Exploit Weaponized · public PoC5
01

Is it exploitable?

— the evidence, ranked above the score
Exploit available
Fully weaponized — public exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
974 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2023-08-07).
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.94508 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Zyxel, P660HN-T1A Routers. Confirm exact fixed builds in the vendor advisory.
NVD ↗Reported
Weakness (CWE)
Mapped to CWE-78 OS Command Injection — weakness family: Injection.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
NVD ↗Reported
02

Who’s exploiting it?

— attribution turns risk into urgency
Attribution not established

No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.

03

Why it matters

— the attack path, told twice: adversary, then board
1

Front door — unauthenticated access narrative 1

Attacker
I identify the ViewLog.asp endpoint as accessible without authentication and craft a malicious remote_host parameter containing shell metacharacters.
Business
Attackers gain direct code execution on network infrastructure, bypassing authentication controls entirely.
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
I execute system commands to establish persistence, exfiltrate configuration data, or pivot to internal network resources.
Business
Compromised routers become persistent attack vectors for lateral movement, data theft, and further network compromise.
3

Lateral reach — past segmentation narrative 3

Attacker
I modify router configurations, redirect traffic, or deploy malware to intercept communications from connected devices.
Business
Organizations lose control of network perimeter security and face exposure of sensitive communications and data.
04

What to do

— defensible action
  • Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05

Coverage & confidence

— what we know, and what we don’t

Established (cited)

  • KEV listing (CISA)
  • EPSS probability (FIRST)
  • Weaponized exploit available (VulnCheck)
  • 974 reported-exploitation source(s)
  • CWE weakness mapping (NVD)
  • Public exploit availability
  • Catalogued by mitre (CNA)
  • Coverage gaps — stated, not hidden

  • No EUVD / GCVE mirror in feed — single-authority dependency for the identifier.
  • EPSS & exposure are time-varying; verify live at the source.
  • Threat-actor attribution not established from feed data — absence of a name is not absence of compromise.
  • No finder/reporter credit recorded in the public CVE entry — the work behind this find is unattributed.
  • Disclosure & credit2
    Catalogued by mitreCNA
    Credited with finding itNo finder named in the public CVE record — the work behind this find is unattributed.