CVE-2023-49556 is a buffer overflow vulnerability identified in YASM version 1.3.0.86.g9def, specifically within the expr_delete_term function located in the libyasm/expr.c component. YASM is an assembler used for compiling assembly language code, often integrated into various software development and reverse engineering tools. The vulnerability arises due to improper handling of memory buffers in the expr_delete_term function, which can be exploited by a remote attacker to cause a denial of service (DoS) condition. The CVSS v3.1 base score is 5.5, indicating a medium severity level. The attack vector is local (AV:L), meaning the attacker must have local access to the system. The attack complexity is low (AC:L), no privileges are required (PR:N), but user interaction is necessary (UI:R). The impact is limited to availability (A:H), with no impact on confidentiality or integrity. There are no known exploits in the wild, and no patches have been linked yet. This vulnerability falls under CWE-120, which relates to classic buffer overflow issues that can lead to memory corruption and application crashes. Given the nature of YASM as a development tool, exploitation would likely require the victim to process maliciously crafted assembly code or input that triggers the vulnerable function, resulting in application crashes or service interruptions.

For European organizations, the primary impact of CVE-2023-49556 is the potential for denial of service in environments where YASM is used. This could affect software development teams, reverse engineering labs, or security researchers who rely on YASM for assembling code. A successful exploitation could disrupt development workflows or automated build systems, leading to downtime and productivity loss. Since the vulnerability requires local access and user interaction, the risk of remote widespread exploitation is limited. However, insider threats or compromised user accounts could leverage this vulnerability to disrupt critical development or analysis processes. Organizations involved in embedded systems, firmware development, or security research may be more exposed. The lack of confidentiality or integrity impact reduces the risk of data breaches, but availability interruptions could delay project timelines or security assessments. Given the medium severity and limited attack vector, the overall impact is moderate but should not be overlooked in sensitive development environments.

To mitigate CVE-2023-49556, European organizations should first identify all instances of YASM in their environments, especially in development and security research teams. Since no official patches are currently linked, organizations should monitor vendor and community channels for updates or patches addressing this vulnerability. In the meantime, restrict local access to systems running YASM to trusted users only, and enforce strict user authentication and authorization policies to prevent unauthorized local access. Educate users about the risk of processing untrusted or malicious assembly code inputs that could trigger the vulnerability. Implement application whitelisting and sandboxing techniques to isolate YASM processes and limit the impact of potential crashes. Additionally, integrate monitoring and alerting for abnormal application behavior or crashes related to YASM to enable rapid response. For build and CI/CD pipelines using YASM, consider adding validation steps or alternative tools until a patch is available. Regularly review and update security policies to include controls for development tools vulnerabilities.