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CVE-2023-43636
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CVE-2023-43636
MITRE ATT&CK
Collection
Command and Control
Credential Access
Defense Evasion
Discovery
Execution
Exfiltration
Impact
Initial Access
Lateral Movement
Persistence
Privilege Escalation
Topic Tags
Description
In EVE OS, the “measured boot” mechanism prevents a compromised device from accessing
the encrypted data located in the vault.
As per the “measured boot” design, the PCR values calculated at different stages of the boot
process will change if any of their respective parts are changed.
This includes, among other things, the configuration of the bios, grub, the kernel cmdline,
initrd, and more.
However, this mechanism does not validate the entire rootfs, so an attacker can edit the
filesystem and gain control over the system.
As the default filesystem used by EVE OS is squashfs, this is somewhat harder than an ext4,
which is easily changeable.
This will not stop an attacker, as an attacker can repackage the squashfs with their changes
in it and replace the partition altogether.
This can also be done directly on the device, as the “003-storage-init” container contains the
“mksquashfs” and “unsquashfs” binaries (with the corresponding libs).
An attacker can gain full control over the device without changing the PCR values, thus not
triggering the “measured boot” mechanism, and having full access to the vault.
Note:
This issue was partially fixed in these commits (after disclosure to Zededa), where the config
partition measurement was added to PCR13:
• aa3501d6c57206ced222c33aea15a9169d629141
• 5fef4d92e75838cc78010edaed5247dfbdae1889.
This issue was made viable in version 9.0.0 when the calculation was moved to PCR14 but it was not included in the measured boot.
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General Information
Vendors
- linuxfoundation
Products
- edge virtualization engine
References
Additional Info
Technical Analysis
Report as Emergent Threat Response
Report as Exploited in the Wild
CVE ID
AttackerKB requires a CVE ID in order to pull vulnerability data and references from the CVE list and the National Vulnerability Database. If available, please supply below: