Merge branch 'fix/crt_bundle_cert_header_oob_v5.5' into 'release/v5.5'

Validate cert header extent before reading it in bundle check (v5.5)

See merge request espressif/esp-idf!52185
This commit is contained in:
Mahavir Jain
2026-09-02 11:52:45 +05:30
@@ -315,6 +315,9 @@ static bool esp_crt_check_bundle(const uint8_t* const x509_bundle, const size_t
// Check all offsets for consistency with certificate data
for (uint32_t i = 0; i < num_certs - 1; ++i) {
const uint32_t off = esp_crt_get_cert_offset(x509_bundle, i);
if (unlikely((uint64_t)off + CRT_HEADER_SIZE > bundle_size)) {
return false;
}
cert_t cert = x509_bundle + off;
// The next offset in the list must point to right after the current cert
const uint32_t expected_next_offset = off + esp_crt_get_len(cert);
@@ -328,7 +331,7 @@ static bool esp_crt_check_bundle(const uint8_t* const x509_bundle, const size_t
// The loop above stops at num_certs - 1, so the final certificate's extent is never
// validated; check it explicitly so its key data cannot run past the bundle (CWE-125).
const uint32_t last_off = esp_crt_get_cert_offset(x509_bundle, num_certs - 1);
if (unlikely(last_off >= bundle_size)) {
if (unlikely((uint64_t)last_off + CRT_HEADER_SIZE > bundle_size)) {
return false;
}
const uint32_t last_len = esp_crt_get_len(x509_bundle + last_off);