Fix heap out-of-bounds read in TPM2_ASN_RsaUnpadPkcsv15#516
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When a PKCS#1 v1.5 padded buffer consists entirely of 0xFF padding bytes after the 0x00 0x01 header, with no 0x00 separator, the padding scan loop exits with idx == *sigSz. The subsequent separator check then dereferenced sig[*sigSz], reading one byte past the end of the buffer. A 3-byte input of 00 01 FF triggers the over-read. Add a bounds check (idx < *sigSz) before dereferencing the separator byte. Fixes wolfSSL#515.
dgarske
approved these changes
Jun 3, 2026
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Add a bounds check (idx < *sigSz) before dereferencing the separator byte. Fixes #515.