Cyber Resilience

CVE-2017-12235

Cisco Ios 12.2 – 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

Summary

CVE-2017-12235 is a high-severity Improper Input Validation (CWE-20) vulnerability in Cisco Ios. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); 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.

A vulnerability in the PROFINET Discovery and Configuration Protocol (PN-DCP) implementation within Cisco IOS versions 12.2 through 15.6 allows an unauthenticated remote attacker to trigger a device reload and resulting denial of service. The flaw stems from improper parsing of specially crafted ingress PN-DCP Identify Request packets and affects any device configured to process PROFINET messages, with PROFINET enabled by default on base switch module and expansion-unit Ethernet ports beginning in release 12.2(52)SE. The issue is tracked as Cisco Bug ID CSCuz47179 and carries a CVSS 3.1 base score of 7.5 due to its impact on availability.

An attacker can exploit the weakness by sending a single crafted PN-DCP Identify Request packet followed by continued legitimate PN-DCP Identify Request traffic, causing the affected device to reload without requiring authentication or user interaction. Successful exploitation produces only a denial-of-service condition and does not permit arbitrary code execution or information disclosure.

The Cisco Security Advisory cisco-sa-20170927-profinet recommends upgrading to a fixed IOS release or disabling PROFINET processing on affected interfaces where feasible, and provides workarounds such as infrastructure access control lists to limit exposure to trusted PROFINET sources.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

A vulnerability in the implementation of the PROFINET Discovery and Configuration Protocol (PN-DCP) for Cisco IOS 12.2 through 15.6 could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition.…

more

The vulnerability is due to the improper parsing of ingress PN-DCP Identify Request packets destined to an affected device. An attacker could exploit this vulnerability by sending a crafted PN-DCP Identify Request packet to an affected device and then continuing to send normal PN-DCP Identify Request packets to the device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. This vulnerability affects Cisco devices that are configured to process PROFINET messages. Beginning with Cisco IOS Software Release 12.2(52)SE, PROFINET is enabled by default on all the base switch module and expansion-unit Ethernet ports. Cisco Bug IDs: CSCuz47179.

CWE(s)
KEV Date Added
03 March 2022

Related Threats

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1036.001 Invalid Code Signature Stealth
Adversaries may attempt to mimic features of valid code signatures to increase the chance of deceiving a user, analyst, or tool.
T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2018-0159Same product: Cisco Iosboth on KEV
CVE-2017-12234Same product: Cisco Iosboth on KEV
CVE-2017-12233Same product: Cisco Iosboth on KEV
CVE-2017-12319Same product: Cisco Iosboth on KEV
CVE-2017-3881Same product: Cisco Iosboth on KEV
CVE-2025-20393Same vendor: Ciscoboth on KEV
CVE-2018-0125Same vendor: Ciscoboth on KEV
CVE-2009-2055Same vendor: Ciscoboth on KEV
CVE-2020-3161Same vendor: Ciscoboth on KEV
CVE-2018-0156Same product: Cisco Iosboth on KEV

Affected Assets

cisco
ios
12.2 — 15.6

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 6 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)

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 (NIST CSF 2.0) AI

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

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require and enforce input validation during development.

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.

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.

prevents

Secure-coding guidelines and mandatory security testing (including code scans) compel developers to validate and sanitize inputs at design and implementation time, lowering the incidence of malformed or malicious data reaching downstream components.

prevents

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.

prevents

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.

none

Regular automated validation of system software and data content, combined with scanning of all inbound files, enforces input validation at the boundary before untrusted content is processed.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

RHEL 8 (1 rule)
  • V-230265 RHEL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-20

References