CVE-2017-12235 is a high-severity vulnerability affecting Cisco IOS versions 12.2 through 15.6. This vulnerability allows an unauthenticated remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. The vulnerability arises from the improper parsing of ingress PN-DCP Identify Request packets directed to the affected device.
To exploit this vulnerability, an attacker can send a crafted PN-DCP Identify Request packet to an affected device and continue to send normal PN-DCP Identify Request packets. A successful exploit could cause the affected device to reload, leading to a DoS condition.
The vulnerability impacts Cisco devices configured to process PROFINET messages. Starting with Cisco IOS Software Release 12.2(52)SE, PROFINET is enabled by default on all base switch module and expansion-unit Ethernet ports. Organizations must prioritize patching immediately to mitigate this risk.
The urgency for defenders is underscored by the vulnerability's inclusion in the Known Exploited Vulnerabilities (KEV) catalog, indicating it is actively being targeted in the wild. Organizations should take immediate action to apply updates as per vendor instructions.
Vulnerability Details
The official description of CVE-2017-12235 reveals that the vulnerability stems from the implementation of the PROFINET Discovery and Configuration Protocol (PN-DCP). Cisco's analysis indicates that the improper handling of PN-DCP Identify Request packets plays a critical role in the vulnerability.
According to the CVSS 3.1 score, this vulnerability has a base score of 7.5, which is classified as high severity. The attack vector is categorized as NETWORK, and the attack complexity is low, indicating that an attacker can exploit this vulnerability without significant effort.
The affected product, Cisco IOS, is widely used in various network environments. This vulnerability has been publicly disclosed on September 29, 2017, and is associated with CWE-20, which pertains to improper input validation.
Technical Analysis
The root cause of CVE-2017-12235 lies in how Cisco IOS processes PN-DCP Identify Request packets. An attacker can leverage this vulnerability by sending malformed packets, which the device fails to handle properly, causing a reload and leading to a DoS condition.
The attack vector is network-based, meaning the attacker does not require physical access to the network infrastructure. The complexity of the attack is low, and no authentication is required, enabling exploitation by unauthorized users.
In terms of impacts, the confidentiality and integrity of the system remain unaffected; however, the availability impact is rated as HIGH, as the device will become non-operational until it is manually restarted.
Risk & Impact Analysis
The real-world risk stemming from CVE-2017-12235 is significant, especially in environments relying on Cisco devices for critical operations. The potential for an unauthorized attacker to disrupt services can lead to operational downtime, data loss, and a negative impact on business continuity.
Given the nature of the vulnerability and its inclusion in the KEV catalog, organizations that have deployed affected Cisco IOS versions should act swiftly. The risk is compounded by the fact that many organizations may not be aware of their exposure to this vulnerability, highlighting the importance of proactive vulnerability management.
Organizations should prioritize remediation based on the CVSS score and the urgency of the situation. Immediate patching is essential to mitigate potential exploitation and safeguard against service disruptions.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | Yes |
Ransomware Use | No |
Affected Versions
The vulnerability affects Cisco IOS versions from 12.2 to 15.6. All versions prior to the vendor patch are considered vulnerable. Organizations should refer to Cisco's guidance for applying the necessary updates.
Mitigation & Remediation
Cisco has provided updates to address this vulnerability. Organizations should apply the updates per vendor instructions. If a patch is not available, consider implementing network controls to limit access to affected devices.
Organizations should also conduct regular monitoring to detect any anomalous behavior that may indicate attempts to exploit this vulnerability. For further guidance on effective remediation strategies, organizations can refer to penetration testing services.
Detection Guidance
Monitoring logs for unexpected reboots or service interruptions can provide indicators of exploitation attempts. Look for patterns of PN-DCP packets arriving in quick succession, which may signify an attack.
Behavioral anomalies in device performance should also be flagged for further investigation. Network signatures associated with known PN-DCP requests may aid in identifying malicious activity.
AppSecure Threat Intelligence Insight
CVE-2017-12235 highlights the ongoing risk associated with misconfigured network protocols. Organizations must ensure proper configuration and validation of all network protocols to mitigate similar vulnerabilities.
The observed trend in network vulnerabilities suggests a need for improved security practices in device configuration. For strategic insights, organizations can refer to resources on vulnerability management and penetration testing methodology to identify and address security gaps.
Furthermore, learning from previous incidents, organizations should be proactive in addressing potential vulnerabilities through regular security assessments and updates.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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