CVE-2023-43630

Technical Description

PCR14 is not in the list of PCRs that seal/unseal the “vault” key, but

due to the change that was implemented in commit

“7638364bc0acf8b5c481b5ce5fea11ad44ad7fd4”, fixing this issue alone would not solve the

problem of the config partition not being measured correctly.

Also, the “vault” key is sealed/unsealed with SHA1 PCRs instead of

SHA256.

This issue was somewhat mitigated due to all of the PCR extend functions

updating both the values of SHA256 and SHA1 for a given PCR ID.

However, due to the change that was implemented in commit

“7638364bc0acf8b5c481b5ce5fea11ad44ad7fd4”, this is no longer the case for PCR14, as

the code in “measurefs.go” explicitly updates only the SHA256 instance of PCR14, which

means that even if PCR14 were to be added to the list of PCRs sealing/unsealing the “vault”

key, changes to the config partition would still not be measured.

An attacker could modify the config partition without triggering the measured boot, this could

result in the attacker gainin

Remediation

Check the references section for vendor advisories and patches from linuxfoundation. Update edge_virtualization_engine to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

Affected Products

References