Threats / Cisco / CVE-2017-6740
CVE-2017-6740
· 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 cause system reboot.
Verdict
Today item — known-exploited.
An authenticated remote attacker can exploit this buffer overflow vulnerability in SNMP to achieve remote code execution or denial of service on affected Cisco devices, with confirmed exploitation in the wild.
01
Is it exploitable?
— the evidence, ranked above the scoreReported exploitation
2 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 2022-03-03).
Probability (EPSS)
EPSS 0.10788 — 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.
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.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution 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 board1
Front door — unauthenticated access narrative 1
Attacker
I gain network access and obtain valid SNMP credentials through phishing or credential compromise.
Business
Network perimeter security is compromised, enabling lateral movement to critical infrastructure.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I send a crafted SNMP message to the target device that triggers a buffer overflow in the SNMP subsystem.
Business
Cisco routing and switching infrastructure becomes vulnerable to direct compromise.
3
Lateral reach — past segmentation narrative 3
Attacker
I execute arbitrary code with device privileges or force an uncontrolled system reload.
Business
Network availability is disrupted and attacker gains persistent control of network infrastructure.
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