CVE-2021-46145Public exploit

Door unlocking via rolling-code counter resynchronization

Published Jan 6, 2022 · Updated Aug 4, 2024

Authentication bypass in the keyfob subsystem of 2012 Honda Civic vehicles allows physically proximate attackers to unlock the doors. The vehicle receiver accepts a consecutive sequence of previously captured rolling-code commands to resynchronize its counter, making expired unlock commands valid again. Exploitation requires capturing keyfob radio transmissions within range and replaying the sequence; the demonstrated consequence is door unlocking, not vehicle operation.

CVSS severity5.3
Medium
EPSS probability3.36%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in the keyfob subsystem of 2012 Honda Civic vehicles allows physically proximate attackers to unlock the doors. The vehicle receiver accepts a consecutive sequence of previously captured rolling-code commands to resynchronize its counter, making expired unlock commands valid again. Exploitation requires capturing keyfob radio transmissions within range and replaying the sequence; the demonstrated consequence is door unlocking, not vehicle operation.

The record

CVE
CVE-2021-46145
Published
Jan 6, 2022
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-294
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 6, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

2.9NIST NVDAV:A/AC:M/Au:N/C:N/I:P/A:N
5.3NIST NVDCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-294Authentication Bypass by Capture-replay

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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