Cyber Resilience

CVE-2023-33281

Auth Bypass in Nissan Sylphy Classic 2021 Firmware

Public PoCAuth Bypass
Published
22 May 2023
Modified
21 November 2024
CVSS Score v3.1 6.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS Score 0.0057 45th percentile
Risk Priority 51 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2023-33281 is a medium-severity Authentication Bypass by Capture-replay (CWE-294) vulnerability in Nissan Sylphy Classic 2021 Firmware. Its CVSS base score is 6.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Network Sniffing (T1040); ranked at the 45th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

The remote keyfob system on Nissan Sylphy Classic 2021 sends the same RF signal for each door-open request, which allows for a replay attack. NOTE: the vendor's position is that this cannot be reproduced with genuine Nissan parts: for example,…

more

the combination of keyfob and door handle shown in the exploit demonstration does not match any technology that Nissan provides to customers.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1040 Network Sniffing Credential Access
Adversaries may passively sniff network traffic to capture information about an environment, including authentication material passed over the network.
T1550.003 Pass the Ticket Lateral Movement
Adversaries may “pass the ticket” using stolen Kerberos tickets to move laterally within an environment, bypassing normal system access controls.
T1550.004 Web Session Cookie Lateral Movement
Adversaries can use stolen session cookies to authenticate to web applications and services.
T1557 Adversary-in-the-Middle Credential Access
Adversaries may attempt to position themselves between two or more networked devices using an adversary-in-the-middle (AiTM) technique to support follow-on behaviors such as [Network Sniffing](https://attack.
T1021 Remote Services Lateral Movement
Adversaries may use [Valid Accounts](https://attack.
T1021.002 SMB/Windows Admin Shares Lateral Movement
Adversaries may use [Valid Accounts](https://attack.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-6374Shared CWE-294
CVE-2026-32053Shared CWE-294
CVE-2025-40807Shared CWE-294
CVE-2025-48012Shared CWE-294
CVE-2023-34625Shared CWE-294
CVE-2023-50786Shared CWE-294
CVE-2023-20900Shared CWE-294
CVE-2024-12839Shared CWE-294
CVE-2025-35057Shared CWE-294
CVE-2026-26232Shared CWE-294

Affected Assets

nissan
sylphy classic 2021 firmware
all versions

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V10.4.16
  • V10.5.1

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-294

Allows detection of capture-replay attacks by showing the replayed logon's timestamp as the last logon.

addresses: CWE-294

Protects against replay of captured session tokens or credentials by requiring authenticated, fresh session channels.

addresses: CWE-294

Wireless link protections commonly incorporate replay protection, reducing the exploitability of capture-replay weaknesses.

addresses: CWE-294

Accurate synchronized time enables tight timestamp windows that directly limit capture-replay windows in authentication protocols.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.AA-04 mostly match
prevents

Protecting and verifying identity assertions prevents replay of captured authentication material.

PR.DS-02 mostly match
prevents

Encryption and integrity protections for data-in-transit directly block capture-replay of credentials or tokens.

DE.CM-01 partial match
prevents

Network monitoring may detect anomalous replays after the fact but does not prevent the design flaw.

PR.AA-03 partial match
prevents

Strong authentication methods can reduce replay risk but do not inherently address captured messages.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Cryptographic protections (e.g., nonces, timestamps, message authentication codes) make captured authentication messages unusable for replay.

prevents

Secure authentication mechanisms directly prevent replay attacks by requiring fresh, non-replayable credentials or tokens.

mitigates

Network security controls such as encryption and integrity protection reduce the feasibility of capturing and replaying authentication traffic.

prevents

Application security requirements can mandate replay-resistant authentication designs, but the control itself does not prescribe the technical measures.

References