CVE-2023-34339

Authentication-header disclosure through exception messages

Published Jun 1, 2023 · Updated Jan 8, 2025

Information exposure in JetBrains Ktor before 2.3.1 allows local users to read authentication headers from exception messages. An undisclosed exception-construction path included authentication-bearing request headers in exception text instead of excluding sensitive header values. Access to an affected application's exception output is required, and the reported impact is limited to disclosure of header-contained credentials.

CVSS severity3.3
Low
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information exposure in JetBrains Ktor before 2.3.1 allows local users to read authentication headers from exception messages. An undisclosed exception-construction path included authentication-bearing request headers in exception text instead of excluding sensitive header values. Access to an affected application's exception output is required, and the reported impact is limited to disclosure of header-contained credentials.

The record

CVE
CVE-2023-34339
Published
Jun 1, 2023
Updated
Jan 8, 2025
Vendor
JetBrains
Product
Ktor
Classifications
CWE-209
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 1, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 8, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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  1. Affected versionversion=0 <2.3.1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

JetBrains · Ktorversion=0 <2.3.1

Published CVSS scores

3.3JetBrainsCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
3.3NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-209Generation of Error Message Containing Sensitive Information

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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