CVE-2023-43632
September 21, 2023
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.
Related Resources (6)
Do you need more information?
Contact UsCVSS v4
Base Score:
9.4
Attack Vector
ADJACENT
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
LOW
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
HIGH
Subsequent System Integrity
HIGH
Subsequent System Availability
HIGH
CVSS v3
Base Score:
9
Attack Vector
ADJACENT
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
CHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Weakness Type (CWE)
EPSS
Base Score:
0.07