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UK Cyber Defence
VulnerabilityAnalyzed

CVE-2018-0171

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

KEVEXPLOITCRITICAL 9.8EPSS 99.5%

Does this matter?

Known to be exploited in the wild (CISA KEV, CISA remediation deadline 3 May 2022). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.

Description

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
9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
99.48% probability · 100th percentile
Public exploits
1 in Exploit-DB · first 29 March 2018
CISA KEV
Listed 3 November 2021 · due 3 May 2022
Weakness
CWE-20, CWE-787
Affected
cisco/ios
Source
psirt@cisco.com
EPSS trend
0%50%100%27 October 2026: 99.48%27 October 202627 October 2026

EPSS 99.5% since 27 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

CISA notes

Apply updates per vendor instructions. https://nvd.nist.gov/vuln/detail/CVE-2018-0171

Public exploits (1)

Entries in Exploit-DB that cite this CVE. Links go to the Exploit-DB page and to the file in the public repository; nothing is hosted here. A verified tick means the Exploit-DB team confirmed the exploit works against the stated version.

EDB-IDTitleTypePublishedVerified
EDB-44451source ↗Cisco Smart Install - Crash (PoC)hardware · embedidos29 March 2018no

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.