CVE-2024-35423 is a heap buffer overflow vulnerability identified in the vmir project, a tool involved in parsing WebAssembly (WASM) modules. The flaw exists in the wasm_parse_section_functions function located in the vmir_wasm_parser.c source file. A heap buffer overflow occurs when the function improperly handles the parsing of the 'section functions' in WASM binaries, leading to an out-of-bounds write in heap memory. This vulnerability is classified under CWE-125 (Out-of-bounds Read), but here it manifests as a heap overflow, which can corrupt memory and potentially allow an attacker to execute arbitrary code, crash the application, or escalate privileges. The CVSS v3.1 score of 7.8 reflects high severity, with an attack vector requiring local access (AV:L), low attack complexity (AC:L), no privileges required (PR:N), but user interaction is necessary (UI:R). The scope is unchanged (S:U), and the impact on confidentiality, integrity, and availability is high (C:H/I:H/A:H). No patches are currently linked, and no known exploits have been reported in the wild. The vulnerability highlights risks in handling untrusted WASM files, which are increasingly used in web and native applications for performance and portability. The lack of authentication requirements and the potential for high-impact exploitation make this a critical concern for developers and organizations relying on vmir or similar WASM parsing libraries.

The impact of CVE-2024-35423 is significant for organizations that utilize vmir or related WASM parsing tools. Exploitation can lead to arbitrary code execution, allowing attackers to run malicious code within the context of the vulnerable application, potentially leading to full system compromise. Additionally, the heap overflow can cause application crashes, resulting in denial of service. Since the vulnerability requires local access and user interaction, the risk is somewhat mitigated but still considerable in environments where untrusted WASM files are processed, such as development environments, CI/CD pipelines, or sandboxed execution contexts. Attackers could craft malicious WASM files to exploit this flaw, targeting developers or automated systems that parse WASM binaries. The high impact on confidentiality, integrity, and availability means sensitive data could be exposed or altered, and critical services disrupted. Organizations that integrate WASM for performance or cross-platform compatibility must consider this vulnerability a serious threat to their software supply chain and runtime security.

To mitigate CVE-2024-35423, organizations should: 1) Immediately restrict processing of untrusted or unauthenticated WASM files within environments using vmir or similar tools. 2) Employ sandboxing techniques to isolate WASM parsing processes, limiting the impact of potential exploitation. 3) Implement strict input validation and boundary checks on WASM binaries before parsing to detect malformed or malicious sections. 4) Monitor and audit usage of vmir and related WASM parsers for unusual behavior or crashes indicative of exploitation attempts. 5) Follow vendor advisories closely and apply patches or updates as soon as they become available. 6) Consider alternative WASM parsing libraries with a strong security track record until a fix is released. 7) Educate developers and system administrators about the risks of processing untrusted WASM content and enforce policies to minimize exposure. 8) Use runtime application self-protection (RASP) or endpoint detection and response (EDR) tools to detect anomalous memory corruption behaviors. These steps go beyond generic advice by focusing on controlling input sources, isolating vulnerable components, and proactive monitoring.