CVE-2019-25550 in Encrypt PDF
Summary
by MITRE • 03/21/2026
Encrypt PDF 2.3 contains a buffer overflow vulnerability that allows local attackers to crash the application by inputting excessively long strings into password fields. Attackers can paste a 1000-byte buffer into the User Password or Master Password field in the Settings dialog to trigger an application crash when importing PDF files.
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Analysis
by VulDB Data Team • 03/21/2026
The vulnerability identified as CVE-2019-25550 resides within the Encrypt PDF 2.3 software component, specifically targeting the handling of password input fields during PDF file import operations. This buffer overflow vulnerability represents a critical security flaw that directly impacts the application's memory management and input validation mechanisms. The flaw manifests when the software processes user-supplied data through the Settings dialog interface, particularly in the User Password and Master Password fields where insufficient bounds checking allows malicious input to exceed allocated memory buffers.
This technical vulnerability operates through a classic buffer overflow mechanism where the application fails to properly validate the length of input data entered into password fields. When an attacker inputs a 1000-byte string into either the User Password or Master Password field, the software's internal buffer allocation cannot accommodate such excessive data, leading to memory corruption and subsequent application instability. The vulnerability is classified as a local privilege escalation risk since it requires user interaction with the application's graphical interface but does not necessitate elevated system privileges to exploit.
The operational impact of this vulnerability extends beyond simple application crashes, potentially enabling more sophisticated attack vectors if the buffer overflow occurs in memory regions that can be manipulated to execute arbitrary code. The flaw aligns with CWE-121, which categorizes buffer overflow conditions where insufficient bounds checking allows data to overwrite adjacent memory locations. This type of vulnerability can be leveraged by attackers to disrupt normal application functionality, potentially leading to denial of service conditions that affect legitimate users attempting to process PDF documents.
From an attack methodology perspective, this vulnerability follows patterns consistent with ATT&CK technique T1203, where adversaries exploit application flaws to cause system instability or crashes. The localized nature of the vulnerability means that exploitation requires physical access to the target system or the ability to influence user behavior through social engineering to encourage interaction with the vulnerable application. The specific 1000-byte threshold suggests that the application's internal buffer allocation is insufficient to handle legitimate password lengths while remaining vulnerable to oversized inputs.
The mitigation strategies for this vulnerability should focus on implementing proper input validation and bounds checking within the application's password handling routines. Software vendors should employ defensive programming techniques including buffer length validation, use of secure string handling functions, and implementation of proper memory management practices. Additionally, regular security assessments and code reviews should be conducted to identify similar buffer overflow vulnerabilities across the application's codebase. Users should be advised to avoid entering excessively long strings into password fields and to ensure their software is updated with patches addressing this specific vulnerability. The remediation process should include comprehensive testing to verify that the patched application properly handles various password length scenarios without crashing or corrupting memory structures.