Full Report
The Tesla charge port is vulnerable to a simple replay attack. The author of this post analyzed the signal deeper. Using GQRX, they captured the signal. From reading the FCC ID, this runs at 315MHz. However, for the recording, you want to use something NOT exactly at 315MHz, just as 315.5MHz. This is because there is always a loud frequency at the center where we want to listen (DC voltage issue). With the recording in hand (raw I/Q data), the author takes to it in Inspectrum. The signal is very clearly using OOK (on off keying). Using the threshold plots, the raw bits can be recovered from the signal. Inspectrum is such an amazing tool! From looking at the recording, a transmission is made up of 3356 symbols with a symbol rate of 2.5kBd. The signal has a preamble of oscillating 0s and 1s. After that, there is a 42 byte charge port signal. These two sections are repeated 10 times each. The author created a GNU radio flow graph for this as well. Simply adding your port number and sending this would open the Tesla! Overall, a cool topic with a fun analysis.
Analysis Summary
# Vulnerability: Tesla Charge Port Replay Attack via Undocumented RF Signal
**Note:** The provided text describes a security research effort analyzing and replicating a radio frequency (RF) signal associated with the Tesla charge port, which facilitates a replay attack. **No official CVE identifiers, severity scores, or vendor patches were detailed in the source material.**
## CVE Details
- CVE ID: N/A (Not assigned in source)
- CVSS Score: N/A (Not provided in source)
- CWE: CWE-575: Improper Initialization of Resource (Implies lack of replay protection or static/predictable commands)
## Affected Systems
- Products: Tesla Vehicle Charge Port Communication System (Remote Control Signal Functionality).
- Versions: Not explicitly specified; assumed to affect systems utilizing the analyzed 315MHz OOK signal for remote port unlocking/control.
- Configurations: Systems relying on the analyzed RF communication for charge port access.
## Vulnerability Description
The Tesla charge port communication signal, operational around 315MHz, was found to be susceptible to a simple **replay attack**. Through analysis using GQRX and Inspectrum, the signal was determined to use On-Off Keying (OOK) modulation. A successful transmission consists of 3356 symbols at a rate of 2.5 kBd, preceded by a preamble of oscillating bits, followed by a consistent 42-byte charge port signal structure. This entire sequence is repeated 10 times. An attacker can capture this raw I/Q data and use tools like GNU Radio to replay the specific sequence, thereby triggering the function (e.g., opening the charge port).
## Exploitation
- Status: Proof-of-Concept (PoC) highly available, as the research includes methods and tools (GNU Radio flow graph) to generate the payload. This is the successful result of the analysis.
- Complexity: Low. The key steps involve simple signal capture (SDR), OOK demodulation, and signal synthesis/transmission, which are well-documented in the provided resources.
- Attack Vector: Adjacent (Requires proximity or line-of-sight for effective capture and replay, depending on hardware power).
## Impact
- Confidentiality: None apparent (Relates to physical access control).
- Integrity: High (An attacker can reliably execute charge port open commands).
- Availability: Low (Attack only affects the charge port mechanism, not vehicle operation).
## Remediation
### Patches
- [No specific vendor patches or version updates were mentioned in the source material.]
### Workarounds
- [No vendor-provided workarounds were detailed in the source material.]
- **Potential Security Measure (Inferred):** The existence of a simple replay capability strongly suggests the need for **rolling codes, nonce inclusion, or authenticated/encrypted communication** in future signal implementations to prevent exact signal repetition.
## Detection
- [No specific IoCs were detailed as this describes a pre-exploitation analysis environment.]
- **Detection Methods (Inferred):** Monitoring for unusually high or repetitive transmissions corresponding to the identified signal structure and frequency (315MHz OOK, 2.5 kBd symbol rate) emanating near the vehicle could potentially indicate malicious activity.
## References
- [Vendor Advisories: None provided]
- Relevant Links:
- GitHub Repository (Analysis Proof of Concept): `github.com/akrutsinger/tesla-charge-port-signal`