CVE-2017-6739 is a high-severity vulnerability in the Simple Network Management Protocol (SNMP) implementation of Cisco IOS and IOS XE Software. This vulnerability allows an authenticated, remote attacker to either cause a reload of the affected system or to remotely execute code. The risk associated with this vulnerability is significant, as it can lead to unauthorized control of the affected system. According to the Common Vulnerability Scoring System (CVSS) version 3.1, this vulnerability has a base score of 8.8, indicating a high level of risk.Attackers may leverage this vulnerability by sending a specially crafted SNMP packet to the affected device. It is important to note that the attacker must know the SNMP read-only community string for SNMP version 2c or earlier, or the user credentials for SNMPv3. The potential for exploitation is concerning, especially as this vulnerability affects all versions of SNMP (versions 1, 2c, and 3).Organizations should prioritize patching immediately. The urgency is underscored by its inclusion in the Known Exploited Vulnerabilities (KEV) catalog, indicating that active exploitation is a concern. The vulnerability was published on July 17, 2017, and its implications are still relevant today, necessitating immediate action from security teams.
Vulnerability Details
The vulnerability in question is due to a buffer overflow in the SNMP implementation of Cisco IOS and IOS XE Software. This buffer overflow issue allows an attacker to send crafted SNMP packets that could lead to arbitrary code execution on the affected systems. The vulnerability affects all versions of SNMP (versions 1, 2c, and 3).The CVSS score of 8.8 indicates a high severity level, which is derived from the metrics indicating that exploitation requires low attack complexity and low privileges. The implications of confidentiality, integrity, and availability are significant, as the potential impacts are rated high across all three categories.The affected products include Cisco IOS and IOS XE Software, with specific version ranges being vulnerable as detailed in the associated configurations. The publication date of the vulnerability was July 17, 2017, and it is categorized under CWE-119, which relates to improper restriction of operations within the bounds of a memory buffer.
Technical Analysis
The root cause of CVE-2017-6739 is a buffer overflow in the SNMP implementation, which can be exploited over a network. The attack vector is network-based, allowing attackers to exploit the vulnerability remotely without needing physical access to the device. The attack complexity is classified as low, meaning that it does not require specialized conditions to exploit.The vulnerability requires low privileges for exploitation, specifically requiring knowledge of the SNMP read-only community string or user credentials. User interaction is not required, which increases the risk as it allows for remote exploitation without needing the victim's assistance.The impacts of successful exploitation include high confidentiality, integrity, and availability impacts. An attacker could execute arbitrary code, leading to complete control of the affected system or causing a reload of the system, potentially leading to downtime and loss of service.
Risk & Impact Analysis
The real-world risk associated with CVE-2017-6739 is substantial, especially considering the widespread use of Cisco IOS and IOS XE Software in various networking environments. The blast radius of this vulnerability is significant, as all devices with SNMP enabled and not properly configured are vulnerable. This could allow an attacker to gain unauthorized access to sensitive network infrastructure.Organizations using affected products must consider this vulnerability a high priority due to the potential for data breaches and network disruptions. The inclusion of this vulnerability in the KEV catalog highlights its urgency. Organizations must act swiftly to apply the necessary updates and mitigate the risks posed by this vulnerability.Given the CVSS score of 8.8 and the associated risks, organizations should address this vulnerability in their priority patch cycle. The potential for exploitation in the wild necessitates immediate attention to safeguard network assets and maintain operational integrity.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | Yes |
Ransomware Use | No |
Affected Versions
The vulnerability affects Cisco IOS versions 12.0 through 12.4, as well as versions 15.0 through 15.6, and Cisco IOS XE versions 2.2.0 through 3.17.0. All versions of SNMP (versions 1, 2c, and 3) are impacted, and any device with SNMP enabled and not properly configured is considered vulnerable.Organizations should consider all versions prior to vendor patch as vulnerable and should act accordingly to ensure their systems are updated.
Mitigation & Remediation
Organizations should apply updates per vendor instructions to mitigate the risks associated with CVE-2017-6739. Immediate patching is recommended to protect against potential exploitation. If a patch is not available, organizations should consider disabling SNMP or configuring it to limit exposure to the affected systems.In addition to applying patches, organizations should implement configuration hardening by restricting SNMP access to trusted IP addresses. Network controls should be put in place to monitor SNMP traffic and detect any anomalies that could indicate an attempted exploitation.For further security validation, organizations may consider engaging in penetration testing to identify additional vulnerabilities that may not be immediately apparent.
Detection Guidance
Organizations should monitor logs for any unusual SNMP traffic patterns that could indicate an attempted exploit. Behavioral anomalies such as unexpected reloads of network devices should be investigated immediately. Network signatures related to SNMP traffic can be implemented to detect potential exploitation attempts.System changes that coincide with SNMP traffic should also be closely monitored to identify any unauthorized changes or behaviors that could indicate a successful exploit.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2017-6739 lies in its representation of vulnerabilities within widely used network management protocols. Security teams should recognize that vulnerabilities in SNMP can lead to serious breaches of network integrity and confidentiality.This vulnerability highlights the necessity for organizations to maintain robust patch management programs and to regularly audit their network configurations. Regular assessments can reveal not only known vulnerabilities but also gaps in security practices that could be exploited.For organizations looking to strengthen their defenses, resources such as the vulnerability management program and the penetration testing methodology can provide strategic frameworks for improving overall security posture.
Furthermore, engaging in API penetration testing and continuous assessment will ensure that defenses remain resilient against emerging threats.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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