security(java): enable fastjson safe mode - #955
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fastjson 1.x parses the "@type" hint even when the target is a JSONObject, and filters it with a deny-list of known gadget classes. wallet-cli feeds untrusted remote payloads into JSON.parseObject (GasFreeApi, MultiSignService, MultiTxWebSocketClient) and never relies on "@type" itself, so force safe mode in Client's static initializer to reject the hint outright. Both the REPL and the standard CLI funnel through Client.main / runMain, so one static block covers both. Defense in depth rather than a patch for a live vulnerability: no published advisory affects 1.2.83. This matches the default fastjson2 ships with. Transaction rendering was the compatibility risk, since a Transaction carries its contract in a protobuf Any. TRON's own JsonFormat prints type_url rather than "@type", guarded by TransactionJsonSafeModeTest.
zerodevblock-cyber
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Jul 20, 2026
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fastjson 1.x parses the "@type" hint even when the target is a JSONObject, and filters it with a deny-list of known gadget classes. wallet-cli feeds untrusted remote payloads into JSON.parseObject (GasFreeApi, MultiSignService, MultiTxWebSocketClient) and never relies on "@type" itself, so force safe mode in Client's static initializer to reject the hint outright. Both the REPL and the standard CLI funnel through Client.main / runMain, so one static block covers both.
Defense in depth rather than a patch for a live vulnerability: no published advisory affects 1.2.83. This matches the default fastjson2 ships with.
Transaction rendering was the compatibility risk, since a Transaction carries its contract in a protobuf Any. TRON's own JsonFormat prints type_url rather than "@type", guarded by TransactionJsonSafeModeTest.