We have identified a possible DoS issue in rust-vmm/vm-superio v0.1.0.
Issue Description
The rust-vmm/vm-superio implementation of the serial console which emulates a UART port type 16550A allows buffering an unlimited number of bytes from input sources when using the FIFO functionality. This issue can not be triggered from the guest side. This issue presents no impact to AWS Services.
Impact
All VMMs that are using the FIFO functionality to forward host-side input from an untrusted source to the guest can be subject to a DoS issue. This issue cannot be triggered from serial output generated by the guest. When no rate limiting is in place, the host can be subject to memory pressure, impacting all other VMs running on the same host. Rate limiting the input from the host side also mitigates the issue.
Affected Systems
rust-vmm/vm-superio v0.1.0.
Proposed Mitigation
Impact can be mitigated by upgrading to vm-superio 0.1.1, configuring memory limits to the process that is using vm-superio, or by rate limiting the writes to the process standard input.
The text was updated successfully, but these errors were encountered:
The fix for #17 includes breaking interface changes.
Updated the version in Cargo.toml so we can publish it to crates.io.
Signed-off-by: Andreea Florescu <fandree@amazon.com>
We have identified a possible DoS issue in rust-vmm/vm-superio v0.1.0.
Issue Description
The rust-vmm/vm-superio implementation of the serial console which emulates a UART port type 16550A allows buffering an unlimited number of bytes from input sources when using the FIFO functionality. This issue can not be triggered from the guest side. This issue presents no impact to AWS Services.
Impact
All VMMs that are using the FIFO functionality to forward host-side input from an untrusted source to the guest can be subject to a DoS issue. This issue cannot be triggered from serial output generated by the guest. When no rate limiting is in place, the host can be subject to memory pressure, impacting all other VMs running on the same host. Rate limiting the input from the host side also mitigates the issue.
Affected Systems
rust-vmm/vm-superio v0.1.0.
Proposed Mitigation
Impact can be mitigated by upgrading to vm-superio 0.1.1, configuring memory limits to the process that is using vm-superio, or by rate limiting the writes to the process standard input.
The text was updated successfully, but these errors were encountered: