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Threats / Cisco / CVE-2017-6742
CVE-2017-6742 · EUVD no mirror located · GCVE no mirror located Verified 2026-06-22

Cisco IOS and XE Software vulnerability

A vulnerability in the SNMP subsystem of Cisco IOS and IOS XE allows authenticated remote attackers to execute arbitrary code or trigger system reloads.

Verdict

Today item — known-exploited.

An authenticated remote attacker can exploit a buffer overflow in SNMP processing to achieve remote code execution or denial of service on affected Cisco devices. This vulnerability has been observed in active exploitation.

CISA KEV Yes · 2023-04-193EPSS 0.21424 (verify live)4
01

Is it exploitable?

— the evidence, ranked above the score
Reported exploitation
10 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 2023-04-19).
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.21424 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Cisco, IOS and IOS XE Software. Confirm exact fixed builds in the vendor advisory.
NVD ↗Reported
Weakness (CWE)
Mapped to CWE-119 Memory Buffer Bounds Error — weakness family: Memory safety.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 authenticate to the SNMP service using valid credentials or bypass authentication controls.
Business
Network infrastructure security is compromised if SNMP credentials are weak or exposed.
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
I craft a malicious SNMP packet that triggers a buffer overflow in the SNMP subsystem processing logic.
Business
Attackers gain code execution capability on critical routing and switching infrastructure.
3

Lateral reach — past segmentation narrative 3

Attacker
I execute arbitrary code with the privileges of the SNMP process or cause the device to reload.
Business
Network availability is disrupted and attackers establish persistent control over network devices.
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)
  • 10 reported-exploitation source(s)
  • CWE weakness mapping (NVD)
  • Catalogued by cisco (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 ciscoCNA
    Credited with finding itNo finder named in the public CVE record — the work behind this find is unattributed.