CVE-2021-42777 in Reports
Summary
by MITRE • 10/31/2022
Stimulsoft (aka Stimulsoft Reports) 2013.1.1600.0, when Compilation Mode is used, allows an attacker to execute arbitrary C# code on any machine that renders a report, including the application server or a user's local machine, as demonstrated by System.Diagnostics.Process.Start.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 11/26/2022
The vulnerability CVE-2021-42777 represents a critical code execution flaw in Stimulsoft Reports versions up to 2013.1.1600.0 that arises specifically when the Compilation Mode feature is enabled. This vulnerability stems from insufficient input validation and sanitization within the report rendering engine, creating a path for remote code execution attacks that can compromise both application servers and end-user machines. The flaw is particularly dangerous because it allows attackers to execute arbitrary C# code during report rendering, effectively bypassing traditional security boundaries that separate client and server environments.
The technical implementation of this vulnerability occurs through the improper handling of user-supplied data within the compilation process of Stimulsoft reports. When Compilation Mode is activated, the system processes report templates and executes embedded code without adequate sanitization of input parameters. Attackers can exploit this by crafting malicious report files that contain specially formatted C# code, specifically leveraging methods like System.Diagnostics.Process.Start to execute arbitrary commands on the target system. This behavior aligns with CWE-94, which describes the weakness of allowing arbitrary code execution through improper input validation. The vulnerability essentially creates a sandbox escape scenario where the report rendering environment becomes a vehicle for executing malicious payloads.
The operational impact of this vulnerability extends beyond simple code execution to encompass complete system compromise across multiple attack vectors. An attacker could potentially execute commands with the privileges of the reporting application, which may run with elevated permissions on the server. This could lead to data exfiltration, persistence mechanisms, lateral movement within the network, or complete system takeover. The vulnerability affects not only the application server where reports are processed but also end-user machines where reports might be rendered locally, making it a particularly dangerous flaw in environments where users might open malicious reports. This aligns with ATT&CK technique T1059.001 for command and script interpreter execution, as the vulnerability enables arbitrary code execution through legitimate system processes.
Organizations should implement immediate mitigations including disabling Compilation Mode if not essential for their operations, implementing strict input validation for all report templates, and conducting comprehensive network segmentation to limit potential attack surfaces. Additionally, regular security updates and patches should be applied as soon as they become available from Stimulsoft. The vulnerability highlights the importance of secure coding practices in report generation libraries and demonstrates why proper input sanitization and privilege separation are critical in application design. Security monitoring should be enhanced to detect unusual process execution patterns that might indicate exploitation attempts, particularly around System.Diagnostics.Process.Start calls. This vulnerability serves as a reminder of the critical security considerations when implementing reporting and data visualization components in enterprise applications.