Security Resilience

CVE-2017-12234

Cisco Ios 12.4 – 15.6

CISA KEVActive ExploitationEUVD Exploited
Published
29 September 2017
Modified
21 April 2026
KEV Added
03 March 2022
Patch / advisory
CVSS Score v3.1 7.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.071 94th percentile
Risk Priority 84 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2017-12234 is a high-severity Improper Input Validation (CWE-20) vulnerability in Cisco Ios. Its CVSS base score is 7.5 (High).

Operationally, ranked in the top 6% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

The vulnerability tracked as CVE-2017-12234 consists of multiple flaws in the Common Industrial Protocol (CIP) implementation within Cisco IOS versions 12.4 through 15.6. These issues stem from improper parsing of specially crafted CIP packets and are identified under Cisco Bug ID CSCvc43709, carrying a CVSS v3 score of 7.5 that reflects a high availability impact with no confidentiality or integrity effects.

An unauthenticated remote attacker can exploit the weaknesses by sending crafted CIP packets to an affected device. Successful exploitation results in a device reload and denial-of-service condition, with the attack vector requiring no user interaction or privileges and being remotely reachable over the network.

The Cisco Security Advisory cisco-sa-20170927-cip, along with related tracking entries at SecurityFocus and SecurityTracker, addresses mitigation steps and software updates for the affected IOS releases. No public information on in-the-wild exploitation is supplied in the available references.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Multiple vulnerabilities in the implementation of the Common Industrial Protocol (CIP) feature in Cisco IOS 12.4 through 15.6 could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. The…

more

vulnerabilities are due to the improper parsing of crafted CIP packets destined to an affected device. An attacker could exploit these vulnerabilities by sending crafted CIP packets to be processed by an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. Cisco Bug IDs: CSCvc43709.

CWE(s)
KEV Date Added
03 March 2022

Related Threats

CVEs Like This One

CVE-2017-12233Same product: Cisco 1000 Integrated Services Routerboth on KEV
CVE-2017-12319Same product: Cisco 1000 Integrated Services Routerboth on KEV
CVE-2018-0159Same product: Cisco Iosboth on KEV
CVE-2017-12235Same product: Cisco Iosboth on KEV
CVE-2017-3881Same product: Cisco Iosboth on KEV
CVE-2018-0125Same vendor: Ciscoboth on KEV
CVE-2009-2055Same vendor: Ciscoboth on KEV
CVE-2025-20393Same vendor: Ciscoboth on KEV
CVE-2020-3161Same vendor: Ciscoboth on KEV
CVE-2017-12240Same product: Cisco 1000 Integrated Services Routerboth on KEV

Affected Assets

cisco
ios
12.4 — 15.6

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-20

Security testing and developer training directly verify and enforce proper input validation, reducing exploitability of injection and malformed-data weaknesses.

addresses: CWE-20

Security testing and evaluation at multiple SDLC stages directly detects missing or flawed input validation, with the required remediation process ensuring fixes are applied.

addresses: CWE-20

Directly implements checks on information inputs to reject invalid data before processing.

addresses: CWE-20

Spam protection mechanisms perform filtering and detection on inbound/outbound messages, directly compensating for missing or weak input validation of unsolicited content.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

blocks

A.8.25 mandates security requirements, secure coding guidelines, checkpoints, testing (incl. code scans) and developer training in the SDLC, which reaches a slice of input validation defects but leaves the majority (incomplete enforcement, second-order inputs, parser differentials, post-validation canonicalization) unaddressed as in the SA-3 and A.8.28 anchors.

blocks

Mandating input controls that include integrity checks and input validation ensures that untrusted data is examined before use, blocking the root cause of many injection and malformed-data weaknesses.

blocks

Security-by-design principles explicitly call for data validation and sanitization at every layer, reducing the chance that malformed or malicious input will be processed without scrutiny.

prevents

Requiring language-specific secure coding standards, peer review, SAST and documented mitigation of common programming errors forces validation of all inputs before they are trusted.

finds

Testing against a defined set of requirements and using code review plus vulnerability scanning forces validation of inputs and handling of unanticipated conditions, reducing the chance that malformed data will be accepted.

Hardening callouts derived

DISA STIG baselines are authored against specific weaknesses. Where this CVE cites a broad weakness class, the mapping is not asserted at that abstraction (owner ruling, 2026-09-25: grade only at Base and below), so no rule is shown here rather than a rule shown against the wrong grain.

  • No fine-grained STIG row for CWE-20, a class-level weakness, and none of its children carries one either.

References