CVE-2018-11595 in Espruino
Summary
by MITRE
Espruino before 1.99 allows attackers to cause a denial of service (application crash) and a potential Escalation of Privileges with a user crafted input file via a Buffer Overflow during syntax parsing, because strncat is misused.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 03/19/2023
The vulnerability identified as CVE-2018-11595 affects Espruino versions prior to 1.99 and represents a critical security flaw that can be exploited to cause application crashes and potentially escalate privileges. This vulnerability arises from improper memory management during the syntax parsing process, specifically through the misuse of the strncat function which is a fundamental string manipulation primitive in C programming. The flaw exists within the embedded JavaScript interpreter that powers Espruino devices, making it particularly concerning for Internet of Things applications and embedded systems where these devices are commonly deployed.
The technical root cause of this vulnerability stems from the improper usage of the strncat function, which is susceptible to buffer overflow conditions when not properly constrained. The strncat function, while designed to prevent buffer overflows by limiting the number of characters copied, becomes dangerous when developers fail to ensure proper initialization of the destination buffer or when the function parameters are incorrectly calculated. In the context of Espruino's syntax parser, this misuse creates a scenario where crafted input files can cause the application to write beyond allocated memory boundaries, leading to unpredictable behavior and system instability. This vulnerability aligns with CWE-121, which categorizes buffer overflow conditions that occur when insufficient space is allocated for data, and specifically relates to CWE-676, which addresses the use of dangerous functions that can lead to memory corruption.
The operational impact of this vulnerability extends beyond simple denial of service, as it can potentially enable privilege escalation attacks on systems running vulnerable Espruino versions. When an attacker crafts malicious input files and feeds them to the vulnerable parser, the buffer overflow can corrupt memory structures and potentially allow execution of arbitrary code. This makes the vulnerability particularly dangerous in environments where Espruino is used for device control, automation, or security-critical applications. The attack surface is broad as Espruino is deployed in various embedded systems, smart home devices, industrial controllers, and educational platforms where attackers could exploit this weakness to gain unauthorized access or cause system-wide disruptions. The vulnerability's exploitation requires minimal privileges and can be executed through simple file uploads or network-based input processing, making it a significant concern for IoT device manufacturers and system administrators.
Mitigation strategies for CVE-2018-11595 primarily focus on upgrading to Espruino version 1.99 or later, which contains the necessary patches to address the buffer overflow condition. Organizations should implement comprehensive patch management procedures to ensure all affected devices are updated promptly, particularly in critical infrastructure environments. Additional defensive measures include input validation and sanitization at all levels of the application stack, implementing proper memory bounds checking, and deploying network segmentation to limit potential attack vectors. The vulnerability also highlights the importance of following secure coding practices and avoiding dangerous functions like strncat in favor of safer alternatives such as strncpy or strlcat, which provide better memory safety guarantees. From an ATT&CK framework perspective, this vulnerability maps to T1059.007 for script-based attacks and T1499.004 for network denial of service, while also potentially enabling T1068 for privilege escalation through memory corruption techniques. System administrators should monitor for suspicious file uploads or network traffic patterns that might indicate exploitation attempts, and implement intrusion detection systems that can identify potential buffer overflow attack signatures.