CVE-2023-39733Network attack vector

Unauthenticated broadcast messaging via leaked client secret

Published Oct 24, 2023 · Updated Sep 11, 2024

Credential disclosure in Linecorp TonTon-Tei Line 13.6.1 allows remote attackers to obtain its channel access token. Public records state that a leaked client secret is exchanged for the token, but do not disclose where the secret is exposed or how it is retrieved. No authentication or user interaction is required, and the resulting token permits crafted broadcast messages to channel recipients.

CVSS severity8.2
High
EPSS probability0.57%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Credential disclosure in Linecorp TonTon-Tei Line 13.6.1 allows remote attackers to obtain its channel access token. Public records state that a leaked client secret is exchanged for the token, but do not disclose where the secret is exposed or how it is retrieved. No authentication or user interaction is required, and the resulting token permits crafted broadcast messages to channel recipients.

The record

CVE
CVE-2023-39733
Published
Oct 24, 2023
Updated
Sep 11, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-269, T1528
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 24, 2023CVE publishedPublication date reported by the CVE source.
  2. Sep 11, 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 vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

8.2INCIBE-CERTCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-269Improper Privilege Management
T1528Steal Application Access Token

Public exploit references

No public exploit references are available in this record.

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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