Threats / Cisco / CVE-2017-3881
CVE-2017-3881
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
Cisco IOS and XE vulnerability
A vulnerability in Cisco IOS and IOS XE Cluster Management Protocol processing allows unauthenticated remote attackers to cause device reloads or execute code with elevated privileges.
Verdict
Today item — known-exploited.
An unauthenticated remote attacker can exploit improper input validation in CMP processing to achieve denial of service or remote code execution on affected Cisco devices. The high EPSS score and active exploitation indicate significant risk.
01
Is it exploitable?
— the evidence, ranked above the scoreExploit 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
5 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 2022-03-25).
Probability (EPSS)
EPSS 0.98975 — 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. Confirm exact fixed builds in the vendor advisory.
Weakness (CWE)
Mapped to CWE-20 Improper Input Validation.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 craft a malicious CMP packet and send it to an exposed Cisco device without authentication.
Business
Network infrastructure becomes unavailable as the device reloads or crashes unexpectedly.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I exploit the input validation flaw to inject code that executes with elevated privileges on the target device.
Business
Attackers gain control of critical network equipment, enabling lateral movement and data exfiltration across the 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