CVE-2021-20035 is a medium-severity vulnerability classified as an OS command injection affecting SonicWall SMA100 appliances. This vulnerability allows improper neutralization of special elements in the management interface, enabling a remote authenticated attacker to inject arbitrary commands as a 'nobody' user. The potential impact includes denial of service (DoS), which can disrupt service availability and lead to significant operational challenges.
With a CVSS score of 6.5, this vulnerability falls into the medium severity category, indicating that while it is not critical, it poses a real threat to organizations that utilize SonicWall's SMA100 appliances. Given the nature of the vulnerability, organizations should assess their exposure and the potential risks involved.
The exploitation status of CVE-2021-20035 indicates no confirmed public exploit, but its presence in the Known Exploited Vulnerabilities (KEV) catalog signifies its potential for exploitation in the wild. Organizations using affected versions of the SonicWall SMA100 appliances should prioritize patching to mitigate this vulnerability.
Organizations should prioritize patching immediately. The remediation of this vulnerability is critical to maintaining the security posture of the environments utilizing these appliances.
Vulnerability Details
The official description of CVE-2021-20035 states that it allows for the improper neutralization of special elements in the SMA100 management interface, permitting a remote authenticated attacker to inject arbitrary commands as a 'nobody' user. This vulnerability falls under CWE-78, which pertains to OS command injection.
The CVSS score for this vulnerability is 6.5, indicating medium severity. The vulnerability is present in various versions of the SonicWall SMA100 firmware, and it was published on September 27, 2021.
Technical Analysis
The root cause of CVE-2021-20035 stems from the improper handling of user input in the management interface of SonicWall SMA100 appliances. This improper neutralization allows attackers to leverage network access to execute commands without proper authorization.
Attack complexity is classified as low, requiring minimal effort to exploit, given that the attacker must possess valid authentication credentials. User interaction is not necessary, which increases the risk of exploitation.
The potential impact on availability is high, as successful exploitation could lead to a complete denial of service. Confidentiality and integrity impacts are not applicable for this vulnerability.
Risk & Impact Analysis
The real-world risk associated with CVE-2021-20035 is significant for organizations utilizing SonicWall SMA100 appliances. The ability for an authenticated attacker to execute arbitrary commands could lead to severe disruptions in service and operational continuity.
Organizations need to understand the blast radius of this vulnerability, as it could affect multiple systems depending on the network architecture and the implementation of the affected appliances. Given the medium CVSS score and its inclusion in the KEV catalog, organizations should assess their risk posture and urgency to remediate.
Risk to organizations includes potential downtime and loss of service availability. Organizations should address this vulnerability in their priority patch cycle to mitigate potential impacts effectively.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | Yes |
Ransomware Use | No |
Affected Versions
The following SonicWall SMA100 firmware versions are affected by CVE-2021-20035:
1. SMA 200 Firmware versions prior to 9.0.0.11-31sv 2. SMA 210 Firmware versions prior to 9.0.0.11-31sv 3. SMA 400 Firmware versions prior to 9.0.0.11-31sv 4. SMA 410 Firmware versions prior to 9.0.0.11-31sv 5. SMA 500v Firmware versions prior to 9.0.0.11-31sv
Mitigation & Remediation
To mitigate the risks associated with CVE-2021-20035, organizations should apply the latest patches as provided by SonicWall. Organizations should follow the vendor's instructions for remediation and ensure that their systems are updated to the latest versions.
If immediate patching is not possible, organizations may consider implementing network controls to limit access to the management interface of the affected devices, thereby reducing the attack surface.
Organizations should also engage in continuous penetration testing to evaluate the security posture of their systems. For further information on effective remediation strategies, refer to our penetration testing services that can assist in identifying vulnerabilities.
Detection Guidance
Security teams should monitor logs for any unauthorized access attempts to the management interface of the SonicWall SMA100 appliances. Behavioral anomalies indicating unusual command execution or service disruptions should also be investigated.
Network signatures can be established to detect potential exploitation attempts, particularly those targeting the command injection flaw. Organizations should maintain vigilance in monitoring system changes that may indicate a compromise.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2021-20035 lies in its representation of the ongoing risk associated with OS command injection vulnerabilities. Such vulnerabilities not only jeopardize immediate system availability but also highlight a broader trend in application security where insufficient input validation leads to severe consequences.
Security teams must recognize the importance of rigorous security practices, including regular penetration testing and thorough code reviews, to identify and mitigate similar vulnerabilities proactively.
For continuous improvement in security posture, organizations should adopt a comprehensive vulnerability management program that includes threat intelligence insights and remediation strategies.
Additionally, organizations can enhance their defensive strategies through penetration testing methodologies that align with current threat landscapes.
Finally, organizations should stay informed about emerging threats and vulnerabilities to ensure their defenses remain robust and effective.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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