CVE-2019-15546 in pancurses Crate
Summary
by MITRE
An issue was discovered in the pancurses crate through 0.16.1 for Rust. printw and mvprintw have format string vulnerabilities.
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Analysis
by VulDB Data Team • 12/04/2023
The vulnerability identified as CVE-2019-15546 affects the pancurses crate version 0.16.1 and earlier in the Rust programming environment. This security flaw manifests within the printw and mvprintw functions, which are commonly used for text output operations within terminal-based applications. The pancurses crate serves as a rust binding for the ncurses library, enabling developers to create text user interfaces and terminal applications that can handle input and output in a structured manner. These functions are particularly critical as they provide formatted output capabilities that are widely utilized in console applications, system monitoring tools, and terminal-based software interfaces.
The technical root cause of this vulnerability stems from improper handling of format strings within the printw and mvprintw function implementations. When developers pass user-controllable input directly into these functions without proper sanitization or validation, the application becomes susceptible to format string attacks. This flaw allows an attacker to inject malicious format specifiers that can cause the program to read from arbitrary memory locations, potentially leading to information disclosure, application crashes, or even arbitrary code execution. The vulnerability aligns with CWE-134, which specifically addresses format string vulnerabilities where format strings are constructed from user-controlled data. These functions do not properly validate or escape input parameters, creating opportunities for attackers to manipulate memory layout through carefully crafted format specifiers.
The operational impact of this vulnerability extends beyond simple application instability, potentially compromising entire system security when exploited. Attackers can leverage this weakness to extract sensitive information from memory segments, including stack contents, heap data, or other application variables that may contain credentials, session tokens, or other confidential data. In terminal-based applications, this could lead to privilege escalation scenarios where attackers gain unauthorized access to system resources or escalate their privileges within the application context. The vulnerability is particularly concerning in environments where pancurses is used for system administration tools, network monitoring applications, or any software that processes untrusted input through these functions. According to ATT&CK framework, this vulnerability maps to T1059.001 (Command and Scripting Interpreter: PowerShell) and T1068 (Exploitation for Privilege Escalation) techniques, as it enables attackers to manipulate application behavior and potentially gain elevated privileges.
Mitigation strategies for CVE-2019-15546 require immediate attention from developers and system administrators. The primary recommendation involves upgrading to pancurses version 0.17.0 or later, where the format string vulnerabilities have been addressed through proper input validation and sanitization. Organizations should implement comprehensive code reviews to identify all instances where printw and mvprintw functions are used with untrusted input, ensuring that all user-supplied data is properly escaped or validated before processing. Additionally, developers should adopt secure coding practices that avoid direct insertion of user-controllable data into format strings, instead using parameterized approaches or explicit format string literals. Security teams should monitor for potential exploitation attempts through log analysis and implement runtime protections such as stack canaries or address space layout randomization to reduce exploit reliability. The remediation process should include thorough regression testing to ensure that the patch does not introduce functional regressions while maintaining the intended terminal interface capabilities.