Threats / Cisco / CVE-2018-0159
CVE-2018-0159
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
Cisco IOS Software and XE vulnerability
A flaw in IKEv1 implementation in Cisco IOS and IOS XE Software allows unauthenticated remote attackers to trigger device reload, causing denial of service.
Verdict
Today item — known-exploited.
An unauthenticated remote attacker can exploit improper input validation in IKEv1 processing to crash affected devices. The vulnerability has been observed in active exploitation. No authentication or user interaction is required.
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 0.06874 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Cisco, IOS Software and Cisco IOS XE Software. 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 malformed IKEv1 packet and send it to the target device's IKE service port.
Business
Network availability is disrupted as the device becomes unreachable during reload.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I repeat the attack against multiple devices in a network to amplify the outage impact.
Business
Critical infrastructure or service continuity is compromised across multiple network segments.
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