CVE-2017-12235
Cisco Ios 12.2 – 15.6
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
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, 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
- 🇪🇺 ENISA EUVD: EUVD-2017-3808
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.…
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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
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Affected Assets
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.
Security testing and developer training directly verify and enforce proper input validation, reducing exploitability of injection and malformed-data weaknesses.
Security testing and evaluation at multiple SDLC stages directly detects missing or flawed input validation, with the required remediation process ensuring fixes are applied.
Directly implements checks on information inputs to reject invalid data before processing.
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.
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.
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.
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.
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.
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.