CVE-2023-26314 in mono
Summary
by MITRE • 02/22/2023
The mono package before 6.8.0.105+dfsg-3.3 for Debian allows arbitrary code execution because the application/x-ms-dos-executable MIME type is associated with an un-sandboxed Mono CLR interpreter.
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Analysis
by VulDB Data Team • 05/19/2026
The vulnerability identified as CVE-2023-26314 represents a critical security flaw in the mono package version 6.8.0.105+dfsg-3.3 and earlier within the Debian ecosystem. This issue stems from an improper MIME type handling mechanism that allows maliciously crafted files to be executed with elevated privileges through the Mono Common Language Runtime interpreter. The vulnerability specifically exploits the association between the application/x-ms-dos-executable MIME type and an un-sandboxed Mono CLR interpreter, creating an attack vector that bypasses normal security boundaries and execution constraints.
The technical root cause of this vulnerability lies in the improper handling of file type associations within the Debian mono package implementation. When a file with the application/x-ms-dos-executable MIME type is processed, the system incorrectly delegates execution to the Mono CLR interpreter without appropriate sandboxing mechanisms. This design flaw allows attackers to craft malicious executables that leverage the full capabilities of the Mono runtime environment, including access to system resources, file operations, and network connectivity. The absence of sandboxing means that code executed through this pathway operates with the privileges of the user running the application, potentially enabling full system compromise.
The operational impact of CVE-2023-26314 extends beyond simple code execution, as it represents a privilege escalation vulnerability that can be leveraged by attackers to gain unauthorized access to systems. This vulnerability particularly affects environments where users might encounter or execute files with the targeted MIME type, such as in email attachments, file sharing systems, or web applications that process user-uploaded content. The attack surface is broadened by the fact that the vulnerability exists in a widely-used package management system, making it potentially exploitable across numerous Debian-based systems including servers, desktop environments, and containerized applications.
The vulnerability aligns with CWE-78 and CWE-74 standards, specifically addressing issues related to command injection and code injection within interpreted environments. From an ATT&CK framework perspective, this vulnerability maps to T1059.001 (Command and Scripting Interpreter: PowerShell) and T1059.007 (Command and Scripting Interpreter: JavaScript) through the exploitation of interpreted runtime environments, though the specific implementation targets the Mono runtime rather than traditional scripting interpreters. The attack vector could be amplified through social engineering techniques where users are tricked into executing malicious files that appear legitimate but contain embedded Mono bytecode or scripts.
Mitigation strategies for CVE-2023-26314 primarily involve upgrading to the patched version of the mono package (6.8.0.105+dfsg-3.3 or later) which implements proper sandboxing controls for the affected MIME type associations. System administrators should also implement additional protective measures including MIME type validation at network boundaries, file extension filtering, and user education regarding suspicious file attachments. Organizations should conduct thorough vulnerability assessments to identify systems running vulnerable versions of the mono package and ensure that all Debian-based systems are updated to prevent exploitation. Network segmentation and access controls should be implemented to limit potential damage if exploitation occurs, while monitoring systems should be deployed to detect anomalous execution patterns that might indicate exploitation attempts.