Vulnerability

CVE-2017-12240

Critical· 9.8KEVCVSS9.8EPSS14%

.rules3/5

Cisco IOS and IOS XE Software DHCP Remote Code Execution Vulnerability

The Dynamic Host Configuration Protocol (DHCP) relay subsystem of Cisco IOS and Cisco IOS XE Software contains a vulnerability that could allow an unauthenticated, remote attacker to execute arbitrary code and gain full control of an affected system.

Threat signal

100/100

Severe

Severity

critical

CVSS

9.8

EPSS

14%

Active

KEV

CISA KEV — actively exploited

1545d overdue

AffectedCisco — IOS and IOS XE 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-2017-12240

CISA description: “The Dynamic Host Configuration Protocol (DHCP) relay subsystem of Cisco IOS and Cisco IOS XE Software contains a vulnerability that could allow an unauthenticated, remote attacker to execute arbitrary code and gain full control of an affected system.”

CVSS

v3.1Open in FIRST calculator →

9.8/ 10CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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 ImpactHighTotal disclosure of sensitive data.
Integrity ImpactHighTotal compromise of integrity — full data modification possible.
Availability ImpactHighTotal loss of availability — full DoS possible.

EPSS

Exploit prediction · 30-day horizonFIRST.org →

13.5%

probability of exploitation in next 30 days

p96

higher than 96% of all CVEs

6-day trend↑ 2.9pp

Above the FIRST 'patch on a priority schedule' threshold.

Vendor VEX

No VEX statements published for CVE-2017-12240. 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: yes
impact: total
mission: support

Lifecycle

2022-03-03Added to CISA KEVransomware: Unknown
2022-03-03Published
2022-03-24Federal patch due (BOD 22-01)
2026-06-15Last modified1 source

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