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CVE DATABASE  /  CVE-2018-0171

CVE-2018-0171

Cisco IOS and IOS XE Software Smart Install Remote Code Execution Vulnerability

CVSS 9.8 · CRITICAL ⚠ CISA KEV — ACTIVELY EXPLOITED
On the CISA KEV catalog

Confirmed exploited in the wild. Added 2021-11-03. Federal remediation due 2022-05-03.
Required action: Apply updates per vendor instructions.

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.

CVSS 3.1 breakdown

Base score9.8 (CRITICAL)
VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vectorNETWORK
Attack complexityLOW
Privileges requiredNONE
User interactionNONE
ScopeUNCHANGED
ConfidentialityHIGH
IntegrityHIGH
AvailabilityHIGH

Weakness type (CWE)

Affected products

Cisco ios
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References

Data: NIST NVD + CISA KEV. NVD last modified 2026-01-14. Always verify against the vendor advisory before acting.

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