How severe is CVE-2018-0171?

CVE-2018-0171 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2018-0171 being actively exploited?

Yes. CVE-2018-0171 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2021-11-03, which means active exploitation has been confirmed. It should be prioritised for remediation.

What products are affected by CVE-2018-0171?

CVE-2018-0171 affects Cisco Ios. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2018-0171?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.

Does CVE-2018-0171 have an EU (EUVD) identifier?

Yes. CVE-2018-0171 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2018-0994. It is also flagged as exploited in the EUVD (since 2021-11-03).

When was CVE-2018-0171 published?

CVE-2018-0171 was published on 2018-03-28 and last updated on 2026-06-17.

CVE-2018-0171

CVE-2018-0171 is a critical-severity vulnerability in Cisco Ios with a CVSS 3.x base score of 9.8. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming it has been exploited in the wild (added 2021-11-03). The underlying weakness is classified as CWE-787.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 10.0
EPSS exploit prediction: 100% (100th percentile)
Actively exploited: Yes — listed in CISA KEV (added 2021-11-03)
EU (EUVD) id: EUVD-2018-0994
EU exploitation: Flagged exploited in the ENISA EU Vulnerability Database (since 2021-11-03)
Weakness: CWE-787
Affected product: Cisco Ios
Published: 2018-03-28
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2018-0171?: 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.
How severe is CVE-2018-0171?: CVE-2018-0171 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2018-0171 being actively exploited?: Yes. CVE-2018-0171 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2021-11-03, which means active exploitation has been confirmed. It should be prioritised for remediation.
What products are affected by CVE-2018-0171?: CVE-2018-0171 affects Cisco Ios. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2018-0171?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.
Does CVE-2018-0171 have an EU (EUVD) identifier?: Yes. CVE-2018-0171 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2018-0994. It is also flagged as exploited in the EUVD (since 2021-11-03).
When was CVE-2018-0171 published?: CVE-2018-0171 was published on 2018-03-28 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:cisco:ios:15.2\(5\)e:*:*:*:*:*:*:*

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