Fix for CWE-122: Heap-based Buffer Overflow #3
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🐕 Corgea issued a PR to fix a vulnerability found in lib/libwasm.c.
It is CWE-122: Heap-based Buffer Overflow that has a severity of 🔴 Critical.
🪄 Fix explanation
The fix mitigates a heap overflow by validating the parameter count before allocation and dynamically allocating the params buffer only for the declared count, preventing overruns beyond the maximum limit of 10 parameters.
- Removed fixed-size allocation "calloc(10, sizeof(WasmValueType))", which risked overflow if actual param_count was larger.
- Added a check "if (entry->param_count > 10) goto parse_error;" to enforce WebAssembly’s maximum parameter limit.
- Allocated "entry->params" dynamically with size based on "entry->param_count" to fit exactly the required parameters.
- Added NULL check after allocation to handle memory failures safely, redirecting to "parse_error" if allocation fails.
💡 Important Instructions
Ensure that the
parse_errorlabel correctly frees any previously allocated resources to avoid memory leaks during error handling.See the issue and fix in Corgea.