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CriticalKEV

CVE-2018-0171 — Cisco IOS and IOS XE Software Smart Install Remote Code Execution Vulnerability

CVE-2018-0171 · Cisco IOS and IOS XE · CVSS 9.8 · KEV

In brief

Severity · CVSS
Critical9.8CVSS 3.1, Critical
EPSS
99%
CISA KEV
Known exploited, listed since 3 Nov 2021
CERT-FR
No advisory or alert referenced in the catalog
Vendor
Cisco
Published · Modified
·
Last verified

Summary

A vulnerability in the Smart Install feature of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to trigger a reload of an affected device, resulting in a denial of service (DoS) condition, or to execute arbitrary code on an affected device. The vulnerability is due to improper validation of packet data. An attacker could exploit this vulnerability by sending a crafted Smart Install message to an affected device on TCP port 4786. A successful exploit could allow the attacker to cause a buffer overflow on the affected device, which could have the following impacts: Triggering a reload of the device, Allowing the attacker to execute arbitrary code on the device, Causing an indefinite loop on the affected device that triggers a watchdog crash. Cisco Bug IDs: CSCvg76186.

Weakness: CWE-20, CWE-787

Title, description and the vendor's statements are quoted from the CVE record; a vendor's advisory is summarised in Patcharo's words, with a link.

Affected and fixed versions

Per product and release branch, as the vendor's CVE record and official advisory state them. A fixed release is shown only when a document names it: the vendor's, or CERT-FR's for Check Point, with its source.

Cisco IOS and IOS XE

Source: CVE-2018-0171cisco-sa-20180328-smi2

  1. —
    Affected versionsCisco IOS and IOS XE
    First fixed releaseNot published in the sources followed

The vendor states fixes are available; the releases per branch are in its advisory.

Remediation

Fix available

Vendor fix

Cisco has released updates that fix this vulnerability; its advisory lists them.

SourceCisco Security Advisory cisco-sa-20180328-smi2· revised 20 Aug 2025

Workarounds (vendor)

Cisco states in its advisory that no workaround is available.

SourceCisco Security Advisory cisco-sa-20180328-smi2

CISA KEV required action

Apply updates per vendor instructions.

CISA due date:

SourceCISA KEV

Last verified 1 Oct 2026 at 09:30 UTC

Known exploitation

Added to CISA KEV on 3 Nov 2021

Federal remediation due date: 3 May 2022

The CISA required action is shown under Remediation.

99% probability of exploitation in the next 30 days (percentile 100%).

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CERT-FR

No CERT-FR advisory or alert of the last two years references this CVE, for the vendors Patcharo covers.

Timeline

  1. Published by the source
  2. Added to CISA KEV
  3. CISA remediation due date
  4. Source record last modified
  5. EPSS score computed
  6. Last verified by Patcharo

Official sources

References

Vendor advisory

Cisco · CISA Known Exploited Vulnerabilities · NVD · FIRST EPSS · Cisco Security Advisory cisco-sa-20180328-smi2

How Patcharo reads this

Affected and fixed releases come from the vendor's structured statements and are matched against exact versions; CVSS from NVD, exploitation from CISA KEV and the vendor's own advisory, probability from FIRST EPSS. Missing data stays Unknown and never becomes Not affected.

Read the methodologyRead the guide: Cisco Secure Firewall release trains: Threat Defense, Management Center and ASA versions explained