CVE-2019-15548 in ncurses Crate
Summary
by MITRE
An issue was discovered in the ncurses crate through 5.99.0 for Rust. There are instr and mvwinstr buffer overflows because interaction with C functions is mishandled.
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Analysis
by VulDB Data Team • 12/04/2023
The vulnerability identified as CVE-2019-15548 resides within the ncurses crate version 5.99.0 and earlier for the rust programming language, representing a critical security flaw that stems from improper handling of interactions between rust code and underlying C functions. This issue manifests through buffer overflow conditions in the instr and mvwinstr functions, which are fundamental components of the ncurses terminal handling library that rust applications utilize for creating text-based user interfaces. The ncurses crate serves as a rust binding to the widely-used ncurses C library, providing developers with capabilities to build sophisticated terminal applications with features like window management, input handling, and screen manipulation.
The technical root cause of this vulnerability lies in the improper memory management and boundary checking when the rust crate interfaces with the native C functions. Specifically, the instr and mvwinstr functions in the ncurses library are designed to read character strings from terminal windows, but due to inadequate buffer size validation and memory allocation handling within the rust wrapper, attackers can potentially exploit this flaw by providing malicious input that exceeds expected buffer limits. This mismanagement creates conditions where the rust code fails to properly validate input lengths before passing data to the underlying C functions, leading to memory corruption that can be leveraged for arbitrary code execution or denial of service attacks.
The operational impact of this vulnerability extends beyond simple application crashes, as it represents a potential path for privilege escalation and system compromise when applications utilizing the affected ncurses crate are deployed in environments where user input is not properly sanitized. Attackers could craft specially formatted input sequences that trigger the buffer overflow conditions, potentially allowing them to overwrite adjacent memory regions and execute malicious code within the context of the vulnerable application. This vulnerability is particularly concerning in terminal-based applications, command-line tools, and system utilities that rely on ncurses for their user interface components, as these applications often run with elevated privileges or handle sensitive data processing tasks.
Mitigation strategies for CVE-2019-15548 should prioritize immediate upgrading to version 5.99.1 or later of the ncurses crate, which contains the necessary patches to address the buffer overflow conditions. Organizations should conduct comprehensive code reviews of applications that utilize the ncurses crate to identify potential attack vectors and implement proper input validation mechanisms. The vulnerability aligns with CWE-121, which addresses stack-based buffer overflow conditions, and may also relate to CWE-122 for heap-based buffer overflows, depending on the specific memory corruption patterns. From an attack surface perspective, this vulnerability could be categorized under ATT&CK technique T1059 for command and scripting interpreter usage, as exploitation might involve manipulating terminal input to trigger the buffer overflow conditions. System administrators should also consider implementing runtime monitoring and input sanitization measures to detect and prevent exploitation attempts, particularly in environments where terminal applications are frequently used.