Description
CCC Attestation SIG attested-tls-poc through commit 731ca82 fails to bind early attestation Evidence to the TLS connection, allowing attackers to relay valid Evidence from a genuine attester. Attackers holding an extracted attested TLS private key can forward the relying party's nonce to a genuine attester and replay its Evidence to impersonate the attested workload and intercept data.
References7
- datatracker.ietf.org/doc/draft-intra-handshake-fail/
- github.com/CCC-Attestation/attested-tls-poc
- github.com/CCC-Attestation/attested-tls-poc/pull/58
- github.com/CCC-Attestation/attested-tls-poc/tree/5b6c5374b3fe8b…
- github.com/ionut-arm/mbedtls/blob/f4ac7593826a506fc509c83cad737…
- github.com/muhammad-usama-sardar/intra-handshake.fail
- www.vulncheck.com/advisories/ccc-attestation-sig-attested-tls-p…
Metrics
- CVSS 3.1
-
7.4
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N - CVSS 4.0
-
9.1
CRITICAL
Score source: CNA
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 0% percentile: 12 · as of 10 November 2026
- CWE
- CWE-346
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.