CVE-2018-25271 in Textpad
Summary
by MITRE • 04/22/2026
Textpad 8.1.2 contains a denial of service vulnerability that allows local attackers to crash the application by supplying an excessively long buffer string through the Run command interface. Attackers can paste a 5000-byte payload into the Command field via Tools > Run to trigger a buffer overflow that crashes the application.
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Analysis
by VulDB Data Team • 05/11/2026
Textpad 8.1.2 suffers from a critical buffer overflow vulnerability that manifests as a denial of service condition when processing user-supplied input through the Run command interface. This vulnerability represents a classic stack-based buffer overflow scenario where the application fails to properly validate input length before processing commands. The flaw occurs specifically within the Command field of the Tools > Run functionality, where attackers can exploit the lack of input sanitization to deliver malicious payloads. The vulnerability is particularly concerning because it requires no elevated privileges to exploit, making it accessible to any local user with access to the application. The 5000-byte payload size demonstrates that the application's input handling mechanism cannot accommodate even moderately sized strings without crashing the process.
The technical implementation of this vulnerability aligns with CWE-121 Stack-based Buffer Overflow, which occurs when a program writes data beyond the bounds of a fixed-length buffer allocated on the stack. This type of vulnerability typically results in memory corruption that causes the application to terminate unexpectedly or behave unpredictably. The exploitation mechanism is straightforward and relies on the application's insufficient input validation routines. When the Run command processes the oversized string, the buffer overflow corrupts adjacent memory locations including stack canaries or return addresses, ultimately leading to application crash. This vulnerability falls under the ATT&CK technique T1499.004 Exploitation for Defense Evasion, as it can be used to disrupt normal application operation and potentially hide more sophisticated attacks.
The operational impact of this vulnerability extends beyond simple application instability, as it can be leveraged as a primitive for more advanced attacks or used to disrupt legitimate user workflows. Local attackers can repeatedly exploit this vulnerability to cause persistent service disruption, making it particularly dangerous in environments where Textpad is used as a primary text editing tool. The vulnerability's accessibility means that any user with local access can potentially crash the application, which could be particularly problematic in shared or multi-user environments. Organizations relying on Textpad for critical documentation or development tasks face potential productivity losses and operational interruptions. The lack of input validation also suggests broader code quality issues that may indicate additional vulnerabilities exist within the application's input processing pathways.
Mitigation strategies should focus on implementing robust input validation and length checking mechanisms within the application's command processing pipeline. The most effective immediate solution involves enforcing strict input length limits on the Command field to prevent buffer overflow conditions. Application developers should implement proper bounds checking and utilize safe string handling functions that prevent buffer overflows. Memory protection mechanisms such as stack canaries, address space layout randomization, and data execution prevention should be enabled to reduce the exploitability of any remaining buffer overflow conditions. Additionally, regular input sanitization should be implemented to filter out potentially malicious strings before processing. Organizations should consider implementing application whitelisting controls to restrict the execution of potentially vulnerable applications and establish monitoring procedures to detect unusual application crash patterns that may indicate exploitation attempts.