CVE-2018-11593 in Espruino
Summary
by MITRE
Espruino before 1.99 allows attackers to cause a denial of service (application crash) and potential Information Disclosure with a user crafted input file via a Buffer Overflow during syntax parsing because strncpy is misused in jslex.c.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 03/19/2023
The vulnerability identified as CVE-2018-11593 affects Espruino versions prior to 1.99 and represents a critical buffer overflow condition that can be exploited to achieve denial of service and potential information disclosure. This flaw resides within the JavaScript lexer component of the Espruino runtime environment, specifically in the jslex.c source file where the strncpy function is improperly utilized. The vulnerability demonstrates characteristics consistent with CWE-121, which describes stack-based buffer overflow conditions, and CWE-125, which addresses out-of-bounds read vulnerabilities. The improper use of strncpy creates a scenario where attacker-controlled input can exceed the bounds of allocated memory buffers during syntax parsing operations.
The technical implementation of this vulnerability occurs during the parsing phase of JavaScript code execution within the Espruino environment. When the system processes user-supplied input files containing specially crafted malicious content, the strncpy function fails to properly enforce buffer boundaries, allowing memory corruption to occur. This memory corruption manifests as application crashes or unexpected behavior, effectively creating a denial of service condition. The flaw is particularly concerning because it can be triggered through normal code parsing operations, making it accessible to attackers who can simply submit malformed JavaScript code to the system.
The operational impact of this vulnerability extends beyond simple service disruption to potentially enable information disclosure attacks. When the buffer overflow occurs, it can overwrite adjacent memory locations containing sensitive data or program state information. This memory corruption may expose internal system details, credentials, or other confidential information that could be leveraged by attackers to escalate their privileges or gain deeper access to the affected system. The vulnerability operates at the application layer and can be exploited remotely if the Espruino environment is accessible over network interfaces, making it particularly dangerous in embedded systems or IoT environments where such devices may be exposed to untrusted input sources.
From an attacker perspective, this vulnerability aligns with ATT&CK technique T1203, which involves exploiting software vulnerabilities to gain access to systems, and T1499, which describes the use of denial of service attacks to disrupt system availability. The exploitation requires minimal privileges and can be automated, making it a preferred attack vector for malicious actors seeking to compromise devices running vulnerable versions of Espruino. Organizations should implement immediate mitigations including upgrading to Espruino version 1.99 or later, where the buffer overflow has been addressed through proper bounds checking and memory management practices. Additionally, input validation mechanisms should be implemented at the application level to sanitize all user-provided code before processing, and system administrators should monitor for unusual application behavior or crash reports that may indicate exploitation attempts.