CVE-2026-82082 in NUMail
Summary
by MITRE • 08/28/2026
NUMail developed by Green-Computing has an OS Command Injection vulnerability. Unauthenticated remote attackers can inject arbitrary OS commands and execute them on the server.
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Analysis
by VulDB Data Team • 08/28/2026
The discovery of a critical operating system command injection flaw within NUMail, a mail management solution developed by Green-Computing, represents a severe compromise to the integrity and availability of affected systems. This vulnerability allows unauthenticated remote attackers to inject arbitrary commands into the application's execution flow, bypassing any necessary input validation or sanitization mechanisms. The absence of authentication requirements for this specific attack vector significantly lowers the barrier to entry for malicious actors, enabling exploitation by virtually any internet-connected user without the need for valid credentials or prior access privileges.
From a technical perspective, command injection vulnerabilities typically arise when an application passes unsafe user-supplied data to a system shell or interpreter. In the context of NUMail, it is likely that one or more input fields are directly concatenated into OS commands without proper escaping or parameterization. When the server processes these inputs, it fails to distinguish between intended program arguments and malicious command sequences. This allows an attacker to terminate the original command and append additional instructions, such as downloading malware, exfiltrating sensitive data, or pivoting to other systems within the network infrastructure. The severity of this flaw is compounded by its remote nature, meaning that exploitation can occur over a network without physical access or local account compromise.
The operational impact of successfully exploiting this vulnerability is catastrophic for organizations relying on NUMail for their communication infrastructure. An attacker with command execution capabilities effectively gains full control over the underlying operating system running the mail server. This level of access enables the theft of confidential email data, including personal identifiable information and corporate secrets stored within the mailbox database. Furthermore, the compromised server can be used as a launchpad for further attacks against internal networks, facilitating lateral movement and potentially leading to widespread ransomware deployment or cryptomining operations that degrade system performance and incur significant financial costs through resource consumption.
This vulnerability aligns closely with Common Weakness Enumeration identifier CWE-78, which specifically defines Improper Neutralization of Special Elements used in an OS Command, commonly known as OS Command Injection. From a tactical standpoint, the exploitation technique corresponds to MITRE ATT&CK techniques related to Remote Services and Command Line Interface abuse, where adversaries leverage existing system tools to execute malicious payloads. The lack of authentication required for this exploit places it among the most dangerous classes of web application vulnerabilities, often cited in frameworks like OWASP Top 10 under Injection flaws that allow direct server compromise.
To mitigate this critical risk, immediate action is required from both administrators and the vendor. Green-Computing should release a patched version of NUMail as soon as possible to address the input validation deficiencies at the code level. In the interim, organizations running vulnerable instances must implement strict network-level controls such as firewall rules that restrict access to the application ports exclusively to trusted IP addresses or virtual private networks. Additionally, deploying Web Application Firewalls with specific signatures for command injection patterns can provide a layer of defense by blocking malicious payloads before they reach the application logic. Regular security audits and static code analysis should be conducted on all custom configurations to ensure no other similar vulnerabilities exist within the deployment environment.