Edge Virtualization Engine
CVE-2023-43632
CRITICAL
Severity by source
AV:N/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:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Lifecycle Timeline
1DescriptionNVD
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. VTPM allows clients to execute tpm2-tools binaries from a list of hardcoded options” The communication with this server is done using protobuf, and the data is comprised of 2 parts:
- Header
- Data
When a connection is made, the server is waiting for 4 bytes of data, which will be the header, and these 4 bytes would be parsed as uint32 size of the actual data to come.
Then, in the function “handleRequest” this size is then used in order to allocate a payload on the stack for the incoming data.
As this payload is allocated on the stack, this will allow overflowing the stack size allocated for the relevant process with freely controlled data.
- An attacker can crash the system.
- An attacker can gain control over the system, specifically on the “vtpm_server” process
which has very high privileges.
AnalysisAI
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. Rated critical severity (CVSS 9.9), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Technical ContextAI
This vulnerability is classified under CWE-789. 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. VTPM allows clients to execute tpm2-tools binaries from a list of hardcoded options” The communication with this server is done using protobuf, and the data is comprised of 2 parts: 1. Header 2. Data When a connection is made, the server is waiting for 4 bytes of data, which will be the header, and these 4 bytes would be parsed as uint32 size of the actual data to come. Then, in the function “handleRequest” this size is then used in order to allocate a payload on the stack for the incoming data. As this payload is allocated on the stack, this will allow overflowing the stack size allocated for the relevant process with freely controlled data. * An attacker can crash the system. * An attacker can gain control over the system, specifically on the “vtpm_server” process which has very high privileges. 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.
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Same technique Denial Of Service
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External POC / Exploit Code
Leaving vuln.today