High severity · published Sep 20, 2023
CVE-2023-43630
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…
8.8
CVSS
0.1%
EPSS
No
On KEV
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 gaining full control over the device with full access to the contents of the encrypted “vault”
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 1% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
EV
Edge Virtualization Engine · Linuxfoundation
9.0.0 before 9.5.0 · source: NVD
Affected product
EV
Edge Virtualization Engine
Linuxfoundation
More from Edge Virtualization Engine
9.9
CVE-2023-43632
As noted in the “VTPM.md” file in the eve documentation, “VTPM is a server listening on port 8877 in EVE, exposing limited functionality of the TPM to the clients
8.8
CVE-2023-43631
On boot, the Pillar eve container checks for the existence and content of “/config/authorized_keys”
8.8
CVE-2023-43636
In EVE OS, the “measured boot” mechanism prevents a compromised device from accessing the encrypted data located in the vault
8.8
CVE-2023-43635
Vault Key Sealed With SHA1 PCRs The measured boot solution implemented in EVE OS leans on a PCR locking mechanism