Vulnerability

CVE-2017-12231

High· 7.5KEVCVSS7.5EPSS9%

.rules3/5

Cisco IOS Software Network Address Translation Denial-of-Service Vulnerability

A vulnerability in the implementation of Network Address Translation (NAT) functionality in Cisco IOS could allow an unauthenticated, remote attacker to cause a denial of service.

Threat signal

86/100

High

Severity

high

CVSS

7.5

EPSS

Active

KEV

CISA KEV — actively exploited

1542d overdue

AffectedCisco — IOS software

Added to KEV

2022-03-03

Federal patch due (BOD 22-01)

2022-03-24

Required action (CISA verbatim)

Apply updates per vendor instructions.

Vendor advisory + references

https://nvd.nist.gov/vuln/detail/CVE-2017-12231

CISA description: “A vulnerability in the implementation of Network Address Translation (NAT) functionality in Cisco IOS could allow an unauthenticated, remote attacker to cause a denial of service.”

CVSS

v3.1Open in FIRST calculator →

7.5/ 10HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack VectorNetworkExploitable remotely over the internet — no local access needed.
Attack ComplexityLowNo special conditions — exploit works reliably.
Privileges RequiredNoneUnauthenticated — no credentials needed.
User InteractionNoneFully automated — no victim action needed.
ScopeUnchangedImpact contained to the vulnerable component.
Confidentiality ImpactNoneNo confidentiality impact.
Integrity ImpactNoneNo integrity impact.
Availability ImpactHighTotal loss of availability — full DoS possible.

EPSS

Exploit prediction · 30-day horizonFIRST.org →

9.35%

probability of exploitation in next 30 days

p93

higher than 93% of all CVEs

3-day trend↑ 0pp

Mid-pack — moderate exploitation likelihood.

Vendor VEX

No VEX statements published for CVE-2017-12231. Vendors publish VEX (Vulnerability Exploitability eXchange) to assert per-product whether a CVE is actually exploitable in their distribution.

SSVCAct

Active exploitation with total impact on essential/support systems

exploitation: active
automatable: no
impact: total
mission: support

Lifecycle

2022-03-03Added to CISA KEVransomware: Unknown
2022-03-03Published
2022-03-24Federal patch due (BOD 22-01)
2026-06-12Last modified1 source

No source-event history recorded yet. New revisions will appear here as ingestors re-fetch this CVE.