Edge Virtualization Engine
CVE-2023-43630
HIGH
Severity by source
AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Lifecycle Timeline
1DescriptionNVD
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”
AnalysisAI
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. Rated high severity (CVSS 8.8), this vulnerability is low attack complexity. No vendor patch available.
Technical ContextAI
This vulnerability is classified under CWE-328. 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” Affected products include: Linuxfoundation Edge Virtualization Engine.
RemediationAI
No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.
More in Edge Virtualization Engine
View allAs noted in the “VTPM.md” file in the eve documentation, “VTPM is a server listening on port 8877 in EVE, exposing limit
On boot, the Pillar eve container checks for the existence and content of “/config/authorized_keys”. Rated high severity
In EVE OS, the “measured boot” mechanism prevents a compromised device from accessing the encrypted data located in the
Vault Key Sealed With SHA1 PCRs The measured boot solution implemented in EVE OS leans on a PCR locking mechanism. Rated
Same weakness CWE-328 – Use of Weak Hash
View allSame technique Information Disclosure
View allShare
External POC / Exploit Code
Leaving vuln.today