CVE-2019-25589 in ZOC Terminal
Summary
by MITRE • 03/22/2026
ZOC Terminal 7.23.4 contains a buffer overflow vulnerability in the Shell field of Program Settings that allows local attackers to crash the application by supplying an excessively long string. Attackers can paste a crafted payload into the Shell configuration field and trigger a crash when accessing the Command Shell feature.
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Analysis
by VulDB Data Team • 03/22/2026
The vulnerability identified as CVE-2019-25589 represents a critical buffer overflow flaw within ZOC Terminal version 7.23.4 that exposes the application to potential local exploitation. This vulnerability specifically targets the Shell field configuration within the Program Settings module, creating a scenario where malicious input can cause arbitrary code execution or application instability. The flaw exists due to inadequate input validation and bounds checking mechanisms that fail to properly handle excessively long string inputs within the designated configuration field.
The technical implementation of this vulnerability stems from improper memory management practices within the application's handling of user-supplied data in the Shell configuration parameter. When a user pastes a crafted payload exceeding the allocated buffer size into the Shell field, the application fails to perform adequate length validation before processing the input. This allows the overflow to occur in the stack or heap memory regions, leading to memory corruption that ultimately results in application crash or potential privilege escalation. The vulnerability is classified as a classic buffer overflow under CWE-121, which specifically addresses stack-based buffer overflow conditions where insufficient bounds checking permits memory writes beyond allocated buffer boundaries. The attack vector is particularly concerning as it requires only local user interaction and can be executed through simple copy-paste operations within the application's interface.
The operational impact of this vulnerability extends beyond simple application instability to potentially compromise system security and availability. Local attackers who can access the application's configuration interface can reliably crash the terminal application, disrupting legitimate user sessions and potentially creating denial of service conditions. In environments where ZOC Terminal serves as a critical communication tool for system administrators or security personnel, such a vulnerability could significantly impact operational continuity and security posture. The vulnerability's local nature means that exploitation does not require network connectivity or external attack vectors, making it particularly dangerous in environments where local access is not strictly controlled. From an adversarial perspective, this vulnerability aligns with ATT&CK technique T1059.001 for Command and Scripting Interpreter and T1499.004 for Endpoint Denial of Service, as it enables both application disruption and potential privilege escalation scenarios.
Mitigation strategies for CVE-2019-25589 should prioritize immediate application updates from the vendor to address the underlying buffer overflow implementation. System administrators should implement strict input validation controls within the application configuration process, including length restrictions and character set limitations for Shell field entries. Additional protective measures include restricting local user access to application configuration interfaces where possible, implementing application whitelisting controls, and monitoring for anomalous configuration changes that might indicate exploitation attempts. The vulnerability demonstrates the importance of input sanitization and bounds checking in preventing memory corruption attacks, emphasizing the need for robust defensive programming practices in terminal and command-line applications. Organizations should also consider implementing network segmentation and access controls to limit local user privileges and reduce the potential impact of such local exploitation vectors. Regular security assessments and code reviews focusing on memory management practices can help identify similar vulnerabilities in other applications and systems within the organization's infrastructure.