CVE-2024-29040Public exploit

Unauthorized access via unchecked attestation magic

Published Jun 28, 2024 · Updated Nov 4, 2025

Improper quote validation in TPM2 Software tpm2-tss 4.0.1 and earlier allows local users to pass forged device attestations. Fapi_VerifyQuote deserializes the TPMS_ATTEST magic field from JSON but fails to require TPM2_GENERATED_VALUE before accepting the signature. Local users must extract a FAPI key and create signed fake attestation data; a relying service can then grant the malicious device unauthorized data or services.

CVSS severity4.3
Medium
EPSS probability0.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper quote validation in TPM2 Software tpm2-tss 4.0.1 and earlier allows local users to pass forged device attestations. Fapi_VerifyQuote deserializes the TPMS_ATTEST magic field from JSON but fails to require TPM2_GENERATED_VALUE before accepting the signature. Local users must extract a FAPI key and create signed fake attestation data; a relying service can then grant the malicious device unauthorized data or services.

The record

CVE
CVE-2024-29040
Published
Jun 28, 2024
Updated
Nov 4, 2025
Vendor
TPM2 Software
Product
tpm2-tss
Classifications
CWE-502
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 28, 2024CVE publishedPublication date reported by the CVE source.
  2. Nov 4, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 4.1.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

TPM2 Software · tpm2-tssversion=< 4.1.0
TPM2 Software · TPM2 Software Stack (tpm2-tss)version=0 <4.1.0

Published CVSS scores

4.3GitHub, Inc.CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-502Deserialization of Untrusted Data

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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