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PatchSiren cyber security CVE debrief

CVE-2017-12240 Cisco CVE debrief

CVE-2017-12240 is a Cisco IOS and IOS XE Software vulnerability described by CISA as a DHCP remote code execution issue. Because it appears in CISA’s Known Exploited Vulnerabilities catalog, it should be treated as a high-priority remediation item for organizations running affected Cisco network software.

Vendor
Cisco
Product
IOS and IOS XE Software
CVSS
Unknown
CISA KEV
Listed
Original CVE published
2022-03-03
Original CVE updated
2022-03-03
Advisory published
2022-03-03
Advisory updated
2022-03-03

Who should care

Network and infrastructure teams responsible for Cisco IOS and IOS XE deployments, especially those managing patching, device lifecycle, and exposure reduction for Cisco routers and switches.

Technical summary

The provided official records identify this issue as a Cisco IOS and IOS XE Software DHCP remote code execution vulnerability. CISA lists it in the Known Exploited Vulnerabilities catalog and directs organizations to apply updates per vendor instructions. No additional technical root-cause details are present in the supplied source corpus.

Defensive priority

High. CISA KEV inclusion indicates known exploitation risk and makes remediation a near-term priority for affected Cisco IOS and IOS XE environments.

Recommended defensive actions

  • Inventory Cisco IOS and IOS XE devices in your environment to determine exposure to CVE-2017-12240.
  • Apply Cisco updates and follow vendor instructions as directed by CISA.
  • Prioritize remediation on internet-facing or business-critical network devices first.
  • Verify patch status after maintenance windows and confirm affected systems are no longer vulnerable.
  • Track this CVE in your vulnerability management program because it is listed in CISA’s KEV catalog.

Evidence notes

This debrief is based only on the supplied CISA KEV source item and official resource links. The source item identifies the vulnerability name, vendor, product, KEV status, date added, due date, and the instruction to apply updates per vendor instructions. The CVE record and NVD link are included as official references, but no additional vendor-advisory details or CVSS data were provided in the corpus.

Sources and references

Verified primary and authoritative sources

  • CVE-2017-12240 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2017-12240

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2017-12240 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2017-12240

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

  • CISA Known Exploited Vulnerabilities catalog

    Publisher, destination, and source semantics verified

    URL: https://www.cisa.gov/known-exploited-vulnerabilities-catalog

    Cybersecurity and Infrastructure Security Agency - Official CISA catalog of vulnerabilities known to be exploited in the wild.

Supplemental references

  • Source item URL

    Unverified legacy reference

    URL: https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json

    cisa_kev

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.