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CVE-2018-0154

Published: Mar 28, 2018Updated: Jan 13, 2026 Sources: CVE List NVD BDUCWE-399
7.5HIGH
NVD MITRE
EPSS Score
7.1%
Top 6.2%
CISA KEV
Active Exploitation
Since Mar 3, 2022
Exploits
No Known Exploits
Remediation
Patch Available
Self-Check
OpenVAS

Description

A vulnerability in the crypto engine of the Cisco Integrated Services Module for VPN (ISM-VPN) running Cisco IOS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to insufficient handling of VPN traffic by the affected device. An attacker could exploit this vulnerability by sending crafted VPN traffic to an affected device. A successful exploit could allow the attacker to cause the affected device to hang or crash, resulting in a DoS condition. Cisco Bug IDs: CSCvd39267.

In plain language

AI Act now

CVE-2018-0154 is a flaw in Cisco IOS VPN (Cisco ISM-VPN) that can let anyone on the network send special VPN traffic to crash or freeze the device—if you use this VPN, you should act now.

Executive summary

CVE-2018-0154 is an unauthenticated, remote denial-of-service in the Cisco ISM-VPN crypto engine on Cisco IOS; it is triggered by sending crafted VPN traffic that the device fails to handle correctly, causing it to hang or crash.

If affected, business impact
VPN outage for employees and customersRemote access disruptionsService downtime and recovery costsPossible inability to process transactions

What to do now

  1. Check whether your Cisco IOS device is using Cisco ISM-VPN for VPN service and whether your software version matches an affected release referenced by Cisco’s advisory for CVE-2018-0154.
  2. If affected, upgrade to the Cisco IOS version that Cisco’s advisory identifies as fixed for CVE-2018-0154.
  3. After updating, test VPN connectivity and verify the VPN service stays stable under normal usage.
  4. If you cannot patch right away, restrict network access to the VPN endpoint (limit who can reach the VPN from the internet or other networks) and monitor for unusual VPN traffic patterns.
Patch / advisory Some work to apply

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:NI:NA:H
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:NConfidentiality
None
I:NIntegrity
None
A:HAvailability
High
Open in CVSS calculator →

Weaknesses

CWE-399NVD-CWE-noinfo

Affected Products

Cisco Systems Inc.
commercial·USaka cisco, cisco systems
Cisco IOSOn-premFirmware
Networking Infrastructure / router-switch
and 2 more affected products View all →

Exploitability

CISA Known Exploited Vulnerability
Added to KEV:Mar 3, 2022
Remediation due:Mar 17, 2022

Required action: Apply updates per vendor instructions.

Official Patch Available
Is your org exposed to CVE-2018-0154?We can run the check for you — a free external exposure review, no install. Check my exposure

References

http://www.securityfocus.com/bid/103559
securityfocus.com
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180328-dos
tools.cisco.com
http://www.securitytracker.com/id/1040585
securitytracker.com
and 4 more references View all →

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