CVE-2023-49992 is a stack buffer overflow vulnerability identified in Espeak-ng version 1.52-dev, a widely used open-source text-to-speech engine. The vulnerability resides in the RemoveEnding function within the dictionary.c source file, where improper handling of input data leads to a stack-based buffer overflow. This type of vulnerability occurs when data exceeding the allocated buffer size is copied onto the stack, overwriting adjacent memory and potentially allowing an attacker to manipulate the program's control flow. Exploitation could enable arbitrary code execution or cause a denial of service by crashing the application. Although no CVSS score has been assigned and no public exploits are currently known, the nature of stack buffer overflows generally makes them critical security issues. Espeak-ng is commonly integrated into accessibility tools, embedded devices, and various software requiring speech synthesis, increasing the attack surface. The lack of patch information suggests that users should monitor official repositories for updates. The vulnerability does not require authentication or user interaction if the input can be controlled by an attacker, raising the risk level. The technical details indicate the issue was reserved on December 4, 2023, and published on December 12, 2023, reflecting recent discovery and disclosure.

For European organizations, the impact of CVE-2023-49992 could be significant, especially for those relying on Espeak-ng in accessibility solutions, embedded systems, or voice-enabled applications. Exploitation could lead to unauthorized code execution, allowing attackers to compromise system integrity, exfiltrate sensitive data, or disrupt services via denial of service. This is particularly critical for sectors such as healthcare, government services, and telecommunications, where speech synthesis technologies are increasingly integrated. The vulnerability could also affect IoT devices and industrial control systems using Espeak-ng, potentially leading to operational disruptions. The absence of known exploits currently limits immediate risk, but the potential for future weaponization remains. European organizations with limited patch management processes or those using development versions of Espeak-ng are at higher risk. Additionally, the vulnerability could be leveraged in supply chain attacks if Espeak-ng is embedded in third-party software distributed within Europe.

Organizations should immediately inventory all systems and applications using Espeak-ng to identify vulnerable versions, particularly 1.52-dev. Until an official patch is released, consider applying temporary mitigations such as input validation and sanitization to restrict untrusted data passed to Espeak-ng components. Employ runtime protection tools like AddressSanitizer or similar memory safety mechanisms during development and testing phases to detect exploitation attempts. Monitor logs and system behavior for anomalies related to speech synthesis processes. Limit network exposure of services utilizing Espeak-ng to reduce attack vectors. Engage with Espeak-ng maintainers and subscribe to security advisories to receive timely patch updates. For embedded and IoT devices, coordinate with vendors to ensure firmware updates address this vulnerability. Additionally, implement strict access controls and segmentation to contain potential compromises. Finally, conduct security awareness training for developers and administrators about safe handling of third-party libraries and dependencies.