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CVE-2017-12240

The DHCP relay subsystem of Cisco IOS 12.2 through 15.6 and Cisco IOS XE Software contains a vulnerability that could allow an…

Critical9.8Known exploitedEPSS 13.8%
Published
Updated
Reserved
Assigned by
cisco

Description

The DHCP relay subsystem of Cisco IOS 12.2 through 15.6 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. The attacker could also cause an affected system to reload, resulting in a denial of service (DoS) condition. The vulnerability is due to a buffer overflow condition in the DHCP relay subsystem of the affected software. An attacker could exploit this vulnerability by sending a crafted DHCP Version 4 (DHCPv4) packet to an affected system. A successful exploit could allow the attacker to execute arbitrary code and gain full control of the affected system or cause the affected system to reload, resulting in a DoS condition. Cisco Bug IDs: CSCsm45390, CSCuw77959.

Exploited in the wild

CISA lists this vulnerability in its Known Exploited Vulnerabilities catalog as Cisco IOS and IOS XE Software DHCP Remote Code Execution Vulnerability.

Added
3 Mar 2022
Fix due (US federal)
24 Mar 2022
Used by ransomware
Not known

Apply updates per vendor instructions.

Scores

CVSS scores of CVE-2017-12240, by who scored it
Scored byCVSSScoreVector
CISA-ADPADP (enrichment)3.1Critical9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVDNVD · Analyzed3.1Critical9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (exploitation in 30 days)
13.8% · top 3.5% of all CVEs (4 Nov 2026)
CISA SSVC
Exploitation: active · Automatable: yes · Technical impact: total
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The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.8.

Weakness

Affected products

  • Cisco IOS and IOS XE

    • affected Cisco IOS and IOS XE

References (6)

Sources

The same CVE in the primary databases and aggregators, to check against.

Badge for a README or a ticket

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Record last updated .