CVE-2017-12232VulnerabilityPublished 03/03/2022Updated 10/24/2026

CVE-2017-12232: Cisco IOS Software for Cisco Integrated Services Routers Denial-of-Service Vulnerability

Affects Cisco IOS softwareSource CISA KEV

Severity

High

No CVSS score published yet

Exploitation: Actively exploited – in CISA KEV since 03/03/2022
KEV deadline: 03/24/2022
EPSS: 2.2% chance of exploitation in 30 days – higher than 82% of CVEs

What to do

CISA required action

Apply updates per vendor instructions.

nvd.nist.gov/vuln/detail/CVE-2017-12232 (opens in a new tab)

Description

CVE-2017-12232 is a denial-of-service vulnerability in Cisco IOS software running on Cisco Integrated Services Routers Generation 2 (ISR G2). An unauthenticated attacker adjacent to the device can exploit a protocol implementation flaw to cause the router to reload, disrupting network availability. This vulnerability has been exploited in the wild.

Summary

This vulnerability exists in the protocol implementation of Cisco IOS software on Cisco ISR G2 routers. It allows an unauthenticated attacker with adjacent network access to trigger a device reload, resulting in denial of service. The flaw is identified as CWE-399 (Resource Management Errors). There is no explicit patch or remediation information provided in the source data. The vulnerability has been observed exploited in the wild, indicating active threat usage.

Impact

Successful exploitation causes the affected Cisco ISR G2 router to reload unexpectedly, leading to denial of service and potential network disruption. Since the attacker does not require authentication and only needs adjacent network access, the risk of disruption is significant in environments using vulnerable devices.

Mitigation

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is applied, network administrators should consider limiting adjacent network access to trusted hosts and monitor for unusual reload events. No official fix or temporary workaround is provided in the available data.

Weaknesses

CWE-399Unclassified weakness (opens in a new tab)

What to do

Description

AnalysisAI-generated, updated 10/24/2026, 10:26:56 UTC

Weaknesses

References

Related threats