For the last 20 years I have been closely working in the SATCOM industry both helping develop prototypes and securing the most critical systems out there so I am pretty interested in research topics in this area.
The recent work by Bisping et al. presents several interesting attack vectors against commercial VSAT satellite modems. The presented software vulnerabilities alone are great, but I want to personally highlight the demonstrated ability to inject spoofed IP traffic into the modem from unexpected angles relative to the dish. This opens a new path for attack satellite modems from the ground which can be use to target individual assets without any involvement with the head end system or using the satellite as a delivery method.
Before exploring the physical part of the research a brief mention to the issues found and a bit of context:
VSAT Basics
A VSAT (Very Small Aperture Terminal) is a compact satellite earth station composed of an outdoor transceiver and an indoor interface that connects users (e.g., PCs) to a central hub via a satellite in a star topology. All user traffic is relayed through the hub, which manages network operations. Modern VSATs, typically 1.2–3 m dishes operating in C‑, Ku‑, and increasingly Ka‑bands, now support multimegabit bi‑directional data, voice, and video services for enterprise and government applications.
Key Vulnerabilities Identified
- Malicious Firmware Update: The unauthenticated update mechanism allows arbitrary firmware to be delivered and (CRC permitting) installed.
- Remote Admin Shell: A buffer‑overflow in the update‑signalization parser yields root shell execution over the air.
Although these software and protocol weaknesses are serious, the real surprise lies in the physical‑layer results—specifically, how off‑axis signal injection can happen from virtually any angle.
Off‑Axis Signal Injection: Angles of Attack
Parabolic VSAT antennas are optimized to receive signals from directly overhead, side‑lobes and back‑lobes still capture off‑axis RF energy. By measuring signal‑to‑noise ratio (SNR) and “acceptance” of injected packets, the study found that in a realworld test with sufficient SDR+BUC power (~9.5 dBm), every angle became viable for injection.
Fig 1. Packet‑injection success rate vs. vertical attack angle (multipath corridor).
These findings underscore that angle‑of‑arrival cannot be relied upon as a sole security boundary, an attacker with an off-the-shelf SDR setup and line of sight to the antenna can breach the link from virtually any direction and exploit vulnerabilities that otherwise would have been only be possible to exploit compromise the head-end system or using the satellite as a delivery channel making the attack easier to detect.
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