CVE-2024-34250 identifies a heap buffer overflow vulnerability in the wasm_loader_check_br function within the Bytecode Alliance wasm-micro-runtime version 2.0.0. This runtime is designed to execute WebAssembly (Wasm) modules efficiently and securely in various environments, including embedded systems, cloud, and edge computing. The vulnerability arises from improper bounds checking during the processing of branch instructions in the WebAssembly bytecode loader, leading to a heap buffer overflow condition. Such a memory corruption flaw can be triggered by a crafted Wasm module, causing the runtime to crash and resulting in a denial of service (DoS) condition. The CVSS v3.1 score is 6.2, reflecting a medium severity primarily due to the impact on availability without compromising confidentiality or integrity. The attack vector is local (AV:L), meaning the attacker must have the ability to supply or influence the Wasm bytecode loaded by the runtime. No privileges are required (PR:N), and no user interaction is necessary (UI:N). The vulnerability is categorized under CWE-122 (Heap-based Buffer Overflow). Currently, no public exploits or patches are available, but the flaw poses a risk to systems embedding this runtime for Wasm execution. The lack of a patch underscores the need for cautious handling of untrusted Wasm modules until remediation is provided.

The primary impact of CVE-2024-34250 is a denial of service condition caused by a heap buffer overflow in the wasm-micro-runtime. For organizations relying on this runtime to execute WebAssembly modules, especially in cloud-native, edge computing, or embedded environments, exploitation could lead to service interruptions or crashes. This may affect availability of critical applications or services that depend on Wasm workloads. Although the vulnerability does not allow for code execution, data leakage, or privilege escalation, the disruption of service can have cascading effects on business operations, particularly in high-availability or real-time systems. The requirement for local access to supply malicious Wasm code somewhat limits the attack surface, but environments that accept untrusted or user-supplied Wasm modules are at higher risk. The absence of known exploits reduces immediate threat but does not eliminate future risk, especially as attackers often develop exploits post-disclosure. Organizations with automated or large-scale Wasm deployments may face increased exposure.

To mitigate CVE-2024-34250, organizations should implement the following measures: 1) Monitor Bytecode Alliance announcements and apply security patches promptly once released. 2) Restrict the execution of untrusted or unauthenticated Wasm modules within the runtime environment to reduce exposure. 3) Employ input validation and sandboxing techniques to limit the impact of malformed Wasm bytecode. 4) Use runtime monitoring and anomaly detection to identify crashes or unusual behavior indicative of exploitation attempts. 5) Where possible, isolate Wasm workloads in separate containers or virtual machines to contain potential denial of service effects. 6) Review and harden deployment configurations to minimize local access vectors that could supply malicious Wasm modules. 7) Engage in threat hunting for any signs of exploitation attempts in environments using wasm-micro-runtime. These steps go beyond generic advice by focusing on controlling the source and execution context of Wasm modules and preparing for rapid patch deployment.