Meta WhatsApp Private Processing

Findings · 28

1. 1 ACS key rotation can de-anonymize users Medium
2. 2 Malicious ACS server can serve invalid signed blinded tokens Medium
3. 3 OHTTP key rotation can de-anonymize users Medium
4. 4 Clients can be targeted by geographic region Informational
5. 5 Sensitive inference-related data can be logged client-side Low
6. 6 Tracked attributes may pose targeting risk Informational
7. 7 Remote attestation lacks freshness guarantees High
8. 8 Reported AMD SEV-SNP TCB version is not checked against VCEK certificate High
9. 9 Client does not enforce all available AMD SEV-SNP Guest Policy protections Informational
10. 10 SEV-SNP attestation is not bound to Meta-specific machines High
11. 11 Use of TLS 1.2 and permissive ciphersuites Informational
12. 12 The system is vulnerable to SNDL attacks by quantum computers Informational
13. 13 CVMs can be compromised via environment variable injection High
14. 14 Insecure rsync usage in configure_cvm.sh Informational
15. 15 Models are stored and loaded as pickle files throughout LLM servers Informational
16. 16 LLM inference output size is not masked Low
17. 17 Malicious hypervisors can inject ACPI SSDTs into CVMs High
18. 18 Lack of CVM image reproducibility hinders third-party review High
19. 19 Private artifact digests do not preserve file structure Low
20. 20 Transparency namespacing not enforced High
21. 21 Transparency artifacts do not expire Informational
22. 22 Unnecessary I/O ports can be exposed to malicious hypervisors Medium
23. 23 Private artifact binary transparency verification may fail silently Low
24. 24 Unpatched Mbed TLS and OpenSSL versions contain known CVEs Informational
25. 25 Spectre mitigations are not enabled in the CVM guest Informational
26. 26 LLM tokenization may leak user data via cache side channels Informational
27. 27 Binary transparency relies on a centralized honest party Informational
28. 28 GPU LLMs do not verify NVIDIA GPU attestation High

Findings extracted from the published report PDF. See the full report below for details and remediation.