GHSA-5x29-3hr9-6wpw is a high-severity (CVSS 7.1) CWE-665 vulnerability in github.com/google/go-tpm. 1 public exploit reference exists, so weaponization risk is real. O3 Security confirms whether GHSA-5x29-3hr9-6wpw is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
TPM 1.2 key authorization values vulnerable to TPM transport eavesdropper in go-tpm
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-5x29-3hr9-6wpw plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 0 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
github.com/google/go-tpmReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Impact
TPM 2.0 users are unaffected by this issue.
An adversary eavesdropping on the TPM 1.2 transport path can calculate usageAuth for a key created with CreateWrapKey, even though this value is encrypted as part of the TPM 1.2 command protocol.
The TPM 1.2 CreateWrapKey command accepts two secrets: usageAuth and migrationAuth. The ADIP protocol (TPM 1.2 specification, part 1, section 13.4) calls for these values to be encrypted with two different XOR keys. Due to a bug in go-tpm prior to version 0.3.0, both usageAuth and migrationAuth are encrypted with the same XOR keystream. This allows an adversary to XOR encUsageAuth and encMigrationAuth together to calculate usageAuth ^ encMigrationAuth. Since migrationAuth is moot for all keys created with go-tpm's CreateWrapKey (since all keys created with this function are marked non-migratable), an adversary may guess or know (from code/binary inspection) that migrationAuth is all 0x00 bytes or some other fixed value. Such an adversary can then calculate usageAuth and use this value later to improperly use the created key, unbeknownst to the creator of the key.
Patches
Fixed in go-tpm version 0.3.0.
Workarounds
- TPM 2.0 users: No workaround needed. This issue only affects TPM 1.2 users.
- TPM 1.2 users: Call CreateWrapKey with a random 20-byte value for
migrationAuth, even though that value is not used again (since CreateWrapKey creates keys that are non-migratable). Do not store or log this value.
Details
TPM 1.2 uses a protocol called ADIP (Authorization Data Insertion Protocol) to encrypt authorization values over-the-wire for newly created objects. This prevents a bus-snooping attack like those publicized by TPM Genie. TPM 2.0 makes this optional (the way to do it is with parameter-encryption sessions). You can read more about ADIP in section 13.4 of Part 1: Design Principles in the latest TPM 1.2 specification. Normally, ADIP consists of the following steps:
Key := SHA1(authSession.SharedSecret || a nonce)
Note: nonces and auth values in TPM 1.2 are always 20 bytes
EncAuth := XOR(Key, Auth)
When commands require one ADIP-encrypted auth value, the nonce is the last nonceEven (last nonce from the TPM). When commands require two ADIP-encrypted auth values, the nonce for the first auth value is still nonceEven, and the nonce for the second auth value is the last nonceOdd, which is the one being provided by the caller along with the current command on the session. The reason for this is that you wouldn't want an adversary to be able to XOR the two encrypted auth values together and come up with (auth 1 XOR key) XOR (auth 2 XOR key) where the "one-time" pad key is used twice and cancels itself out.
Here are the commands that take one authorization value by ADIP:
- Seal (the sealed data's auth value)
- Sealx (the sealed data's auth value)
- CreateKey (the key's auth value)
- MakeIdentity (the AIK's auth value)
- ChangeAuth (the entity's new auth value)
- ChangeAuthOwner (the new owner auth value)
- Delegate_CreateKeyDelegation (the new delegation auth value)
- Delegate_CreateOwnerDelegation (the new delegation auth value)
- NV_DefineSpace (the NV's auth value)
- CreateCounter (the counter's auth value)
Here are the commands that take two authorization values by ADIP:
- CreateWrapKey (the key's auth value, and the key's migration (to export out of the TPM) auth value)
The migrationAuth value is never used if the key does not have the TPM_KEY_FLAGS.migratable flag set on it. go-tpm does not currently allow the caller to set this flag.
Here was the bug in our implementation of CreateWrapKey():
Here we see that both usageAuth and migrationAuth are encrypted by the same XOR key. This is the correct key (i.e., it is based on nonceEven) for usageAuth, but not migrationAuth.
This means 2 things:
First: migrationAuth is being set to some value that is effectively unrelated to migrationAuth as passed by the caller. Again, this is not interesting to all current callers (given that there is no way for them to pass TPM_KEY_FLAGS.migratable via the current API; migrationAuth is not a meaningful value).
Second, and much more importantly: a user of go-tpm is vulnerable to the following attack by a passive bus-snooping adversary (CVE-2020-8918)
- Wait for a
CreateWrapKeycommand - Collect
encUsageAuthandencMigrationAuth - Calculate
(usageAuth XOR migrationAuth) := (encUsageAuth XOR encMigrationAuth) - Assuming migrationAuth is all 0x00 (a reasonable assumption for a caller who knows the key is not migratable), the calculation in (3) is the usage auth of the key.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/google/go-tpm | all versions | 0.3.0 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/google/go-tpm. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/google/go-tpm to 0.3.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-5x29-3hr9-6wpw is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-5x29-3hr9-6wpw is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-5x29-3hr9-6wpw. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-5x29-3hr9-6wpw in your dependencies?
O3 detects GHSA-5x29-3hr9-6wpw across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.