CVE-2021-27561 is a critical command injection vulnerability affecting Yealink Device Management (DM) version 3.6.0.20. This vulnerability allows command injection as root via the /sm/api/v1/firewall/zone/services URI, without authentication. The CVSS score of 9.8 underscores the severity of this issue, indicating that organizations must prioritize remediation to mitigate potential attacks.
The risk to organizations includes unauthorized access to sensitive systems and data, which could lead to significant operational disruptions and data breaches. Given the ease of exploitation, immediate action is critical to ensure system integrity and confidentiality.
As of now, there is no confirmed public exploit for this vulnerability, but its inclusion in the Known Exploited Vulnerabilities (KEV) database highlights its potential risk. Organizations must remain vigilant and proactive in their patching efforts.
Organizations should prioritize patching immediately to protect against the risks associated with CVE-2021-27561.
Vulnerability Details
The official CVE description states that "Yealink Device Management (DM) 3.6.0.20 allows command injection as root via the /sm/api/v1/firewall/zone/services URI, without authentication." This vulnerability is classified under CWE-78 (Improper Neutralization of Special Elements used in an OS Command ('Command Injection')).
The vulnerability has a CVSS 3.1 score of 9.8, indicating a critical severity level. The components affected include the Yealink Device Management software. It was published on October 15, 2021, and is currently analyzed in the context of security risks.
Technical Analysis
The root cause of this vulnerability lies in the software's failure to properly sanitize user inputs, allowing attackers to inject arbitrary commands. The attack vector is network-based, meaning that no local access is required for exploitation. The complexity of the attack is low, as the attacker does not need any special privileges or user interaction to exploit the vulnerability.
The impacts on confidentiality, integrity, and availability are all rated as high, indicating that successful exploitation can lead to complete compromise of the affected system.
Risk & Impact Analysis
The deployment risk associated with CVE-2021-27561 is significant, particularly for organizations that utilize Yealink Device Management systems. The potential for widespread damage increases, given the high CVSS score and the nature of the vulnerability.
This vulnerability is especially concerning due to its ability to allow attackers to execute arbitrary commands remotely. The blast radius could potentially affect any organization using the vulnerable version of the software.
Given its critical nature, organizations must assess their exposure and prioritize patching this vulnerability as part of their security posture.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | Yes |
Ransomware Use | No |
Affected Versions
The affected product is Yealink Device Management (DM) version 3.6.0.20. All versions prior to this patch are vulnerable.
Mitigation & Remediation
Organizations should apply updates per vendor instructions to remediate this vulnerability. For those unable to apply patches immediately, consider implementing network controls to restrict access to vulnerable services.
For further guidance on effective remediation strategies, organizations may refer to best practices in penetration testing and security assessments, such as those outlined in our penetration testing services that can help identify and mitigate similar vulnerabilities.
Detection Guidance
To detect potential exploitation of this vulnerability, organizations should monitor logs for unusual command execution patterns and unauthorized API access attempts. Behavioral anomalies around network traffic targeting the affected endpoints should also be investigated.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2021-27561 lies in its demonstration of the risks associated with command injection vulnerabilities in network-facing applications. This incident serves as a reminder for security teams to regularly assess their software for similar weaknesses and to establish robust input validation practices.
Organizations should implement a comprehensive vulnerability management program to continuously identify, assess, and remediate vulnerabilities. For further insights, review our articles on vulnerability management and the importance of penetration testing methodologies in strengthening your security posture.
Additionally, organizations should remain informed about ongoing trends in vulnerabilities and threat landscapes, such as those discussed in our vulnerability exposure trends to better anticipate and respond to 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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