CVE-2026-83948 in Azure CLI
Summary
by MITRE • 09/09/2026
Improper neutralization of special elements used in a command ('command injection') in Microsoft Azure CLI allows an authorized attacker to execute code over a network.
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Analysis
by VulDB Data Team • 09/09/2026
The vulnerability identified as improper neutralization of special elements used in a command, commonly referred to as Command Injection, represents a critical security flaw within the Microsoft Azure Command-Line Interface (Azure CLI). This type of vulnerability arises when software constructs operating system commands using externally influenced input without sufficiently validating or sanitizing that data. In this specific instance, an authorized attacker who has access to the Azure CLI environment can exploit this weakness by injecting malicious command sequences into inputs that are subsequently passed to underlying shell interpreters. The core technical flaw lies in the failure of the application to properly escape or neutralize special characters such as semicolons, ampersands, pipes, and backticks, which hold significant meaning for command-line processors. When these characters are not handled correctly, they allow an attacker to break out of the intended context of a command and append arbitrary operating system commands that will be executed with the privileges of the user running the Azure CLI process.
From a technical perspective, this vulnerability aligns directly with CWE-78, which defines Improper Neutralization of Special Elements used in an OS Command. The exploitation mechanism typically involves identifying parameters or arguments within Azure CLI commands where user-supplied data is concatenated into shell command strings rather than being passed as distinct arguments to executable binaries. For example, if a script or internal function uses string formatting to build a system call like os.system("azure_command " + userInput), an attacker could supply input such as "; rm -rf /" which would result in the execution of both azure_command and the destructive removal command. This lack of separation between code and data is a fundamental design error that undermines the integrity of the execution environment. The vulnerability allows for remote code execution, albeit requiring initial authentication or access to the CLI session, making it particularly dangerous in environments where developers or administrators manage cloud resources through automated scripts or interactive sessions.
The operational impact of this command injection flaw is severe, as it grants an attacker full control over the host system running the Azure CLI instance. Depending on the permissions assigned to the user account executing the CLI tool, the injected commands can range from simple information gathering to complete compromise of the underlying infrastructure. An attacker could exfiltrate sensitive configuration files, modify cloud resource settings via subsequent API calls triggered by shell scripts, install persistent backdoors, or pivot into other parts of the network if the compromised host has broader connectivity. This effectively bypasses the intended security boundaries of the Azure platform itself, as the CLI acts with the credentials and permissions of the logged-in user. In a DevOps context where CI/CD pipelines often run automated scripts using service principals or managed identities, this vulnerability could lead to widespread compromise across multiple cloud subscriptions if the pipeline environment is not properly isolated.
This incident maps closely to several techniques within the MITRE ATT&CK framework for both on-premises and cloud environments. Specifically, it corresponds to T1059 Command and Scripting Interpreter, which covers the use of shell commands or scripts to execute malicious code. Furthermore, because Azure CLI interacts with Microsoft Graph API and other service endpoints, successful exploitation may also facilitate lateral movement or privilege escalation within the identity layer if subsequent commands are crafted to abuse OAuth tokens or managed identities. The attack vector is classified as Network-based but requires user interaction in the form of providing specific inputs to the CLI tool, placing it at a medium level of complexity for initial access unless automated tools are used against exposed endpoints that invoke CLI functions internally.
Mitigation strategies must focus on both immediate remediation and long-term architectural improvements. The primary defense is to ensure that all versions of Azure CLI affected by this vulnerability are updated to the latest patched release provided by Microsoft, which should implement strict input validation and use safe APIs for command execution rather than shell interpretation. Developers integrating Azure CLI into custom automation tools must avoid using system-level command concatenation functions like os.system or subprocess.call with shell=True when processing untrusted data. Instead, they should utilize subprocess.run with a list of arguments to ensure that inputs are treated strictly as data parameters and not as executable code fragments. Additionally, implementing least-privilege principles for the accounts running Azure CLI can limit the blast radius if an injection attempt succeeds by restricting access to critical resources and sensitive operations. Regular auditing of scripts and automated workflows for unsafe command construction practices is also essential to prevent similar vulnerabilities from being introduced in custom tooling that relies on the CLI interface.