CVE-2020-15415 is a critical vulnerability affecting DrayTek Vigor3900, Vigor2960, and Vigor300B devices. This vulnerability allows remote command execution via shell metacharacters in a filename when the text/x-python-script content type is used. The flaw exists in the cgi-bin/mainfunction.cgi/cvmcfgupload component of the affected firmware versions, specifically those prior to 1.5.1. Given the severity of the vulnerability, organizations must take immediate action to mitigate the associated risks.
With a CVSS score of 9.8, this vulnerability is classified as critical. The attack vector is network-based, and it requires no privileges or user interaction, making it particularly dangerous. Risk to organizations includes potential unauthorized access and manipulation of sensitive data, which could lead to significant operational disruptions and reputational damage.
Currently, there are no confirmed public exploits available for this vulnerability, but given its presence in the Known Exploited Vulnerabilities (KEV) catalog, organizations should prioritize patching immediately. The urgency is heightened by the vulnerability's potential to be exploited remotely without the need for authentication.
Organizations utilizing the vulnerable DrayTek devices must assess their risk exposure and take appropriate measures as outlined in vendor advisories. Ensuring that devices are updated to the latest firmware version is critical to safeguarding against this vulnerability.
Vulnerability Details
The vulnerability allows remote command execution through the cgi-bin/mainfunction.cgi/cvmcfgupload interface. If an attacker manages to exploit this vulnerability, they can execute arbitrary commands on the server, leading to full compromise of the affected systems.
The CVSS score of 9.8 indicates critical severity, reflecting the high potential impact on confidentiality, integrity, and availability. The vulnerability is classified under CWE-78, which pertains to OS command injection issues.
The devices affected by this vulnerability include the DrayTek Vigor3900, Vigor2960, and Vigor300B, all of which require immediate updates to version 1.5.1 or later.
Technical Analysis
The root cause of this vulnerability lies in the improper handling of user-supplied input in the filename field. Attackers may leverage this flaw by injecting malicious shell commands within the filename, leading to command execution on the underlying operating system.
The attack vector is network-based, and the complexity is low, meaning that even attackers with minimal skills can exploit it. The privileges required are none, and user interaction is not necessary, making it an attractive target for attackers.
The impacts of successful exploitation include high confidentiality, integrity, and availability impacts, as the attackers can execute arbitrary commands, potentially leading to complete system takeover.
Risk & Impact Analysis
Real-world deployment of vulnerable DrayTek devices in critical infrastructure or corporate environments poses significant risks. Organizations should assess the blast radius of this vulnerability, as attackers could gain access to sensitive data and systems, leading to potential data breaches and operational disruptions.
The urgency for organizations to address this vulnerability is critical, given the high CVSS score and the potential for exploitation. The fact that it is included in the KEV catalog emphasizes the need for immediate action to mitigate risks.
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | Yes |
Ransomware Use | No |
Affected Versions
The affected versions of DrayTek products include all versions prior to 1.5.1 for Vigor3900, Vigor2960, and Vigor300B devices. Organizations must update to the latest firmware to mitigate this vulnerability.
Mitigation & Remediation
Organizations should apply vendor patches immediately. For DrayTek devices, upgrade to firmware version 1.5.1 or later to remediate the vulnerability. If a patch is unavailable, organizations must consider discontinuing the use of affected products until a fix is applied.
Additionally, implementing configuration hardening and network controls can help mitigate risks until patches are applied. Regular monitoring for unauthorized access attempts is also recommended.
Organizations should consider engaging in penetration testing to evaluate the effectiveness of their security measures against potential exploitation.
Detection Guidance
Monitoring logs for unusual activity, particularly around the cgi-bin/mainfunction.cgi interface, is crucial. Behavioral anomalies indicating potential command injection attempts should be investigated promptly. Network signatures associated with known attack patterns may also assist in early detection.
AppSecure Threat Intelligence Insight
This vulnerability exemplifies the risks associated with inadequate input validation and handling in web applications. Security teams should prioritize implementing robust input validation mechanisms to prevent similar vulnerabilities. The ongoing trend of vulnerabilities related to command injection calls for heightened scrutiny during the development and deployment phases of software.
Organizations are encouraged to establish a comprehensive vulnerability management program to proactively address future vulnerabilities.
Regularly reviewing and updating security policies, alongside engaging in penetration testing practices, can significantly enhance an organization's security posture.
The critical nature of CVE-2020-15415 serves as a reminder for security teams to remain vigilant and responsive to emerging threats in their environments.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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