CVE-2023-43632 Freely Allocate Buffer on The Stack With Data From Socket
An attacker can crash the system or execute arbitrary code with high privileges by sending a large size header to the VTPM server, causing a stack buffer overflow.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-43632?
CVE-2023-43632 is a critical memory corruption vulnerability in EVE OS, published on 21 Sep 2023. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2023-43632?
3 open source packages ship an affected version, including github.com/lf-edge/eve. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/lf-edge/eve Go | All versions | 0.0.0-20230519072751-977f42b07fa9 |
github.com/lf-edge/eve Go | All versions | 0.0.0-20230519072751-977f42b07fa9 |
github.com/lf-edge/eve Go | All versions | 0.0.0-20230519072751-977f42b07fa9 |
Products include Linuxfoundation Edge Virtualization Engine.
How do I fix CVE-2023-43632?
Upgrade github.com/lf-edge/eve to 0.0.0-20230519072751-977f42b07fa9 or later.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2023-43632 being exploited?
There is no known exploitation of CVE-2023-43632 in the wild and no public exploit code.
Other vulnerabilities in EVE OS
Sources
Also known as GHSA-6jp5-grgh-jw42, GO-2026-4422.