This repository hosts source code implementing the Trusted Computing Groups (TCG) TPM2 Software Stack (TSS). The JSON Quote Info returned by Fapi_Quote has to be deserialized by Fapi_VerifyQuote to the TPM Structure TPMS_ATTEST. For the field TPM2_GENERATED magic of this structure any number can be used in the JSON structure. The verifier can receive a state which does not represent the actual, possibly malicious state of the device under test. The malicious device might get access to data it shouldnt, or can use services it shouldnt be able to. This
issue has been patched in version 4.1.0.
The product deserializes untrusted data without sufficiently verifying that the resulting data will be valid.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Tpm2-tss | Ubuntu | devel | * |
| Tpm2-tss | Ubuntu | jammy | * |
| Tpm2-tss | Ubuntu | mantic | * |
| Tpm2-tss | Ubuntu | noble | * |
| Tpm2-tss | Ubuntu | upstream | * |
It is often convenient to serialize objects for communication or to save them for later use. However, deserialized data or code can often be modified without using the provided accessor functions if it does not use cryptography to protect itself. Furthermore, any cryptography would still be client-side security – which is a dangerous security assumption. Data that is untrusted can not be trusted to be well-formed. When developers place no restrictions on “gadget chains,” or series of instances and method invocations that can self-execute during the deserialization process (i.e., before the object is returned to the caller), it is sometimes possible for attackers to leverage them to perform unauthorized actions, like generating a shell.