CVE-2023-5339

Credential disclosure via first-run keystroke logging

Published Oct 17, 2023 · Updated Sep 5, 2024

Sensitive-data exposure in Mattermost Desktop 5.4.0 and earlier allows local users to read logged keystrokes after a fresh installation. On its initial run, the Desktop client leaves logging at an overly verbose level and writes every keystroke, including password input, to its log. Exposure requires a user to type sensitive data during that first-run state and local access to the resulting log.

CVSS severity4.7
Medium
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Sensitive-data exposure in Mattermost Desktop 5.4.0 and earlier allows local users to read logged keystrokes after a fresh installation. On its initial run, the Desktop client leaves logging at an overly verbose level and writes every keystroke, including password input, to its log. Exposure requires a user to type sensitive data during that first-run state and local access to the resulting log.

The record

CVE
CVE-2023-5339
Published
Oct 17, 2023
Updated
Sep 5, 2024
Vendor
Mattermost
Product
Mattermost
Classifications
CWE-200, CWE-532, T1552.001
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 17, 2023CVE publishedPublication date reported by the CVE source.
  2. Sep 5, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=5.4.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Mattermost · Mattermostversion=0 <=5.4.0

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
4.7MattermostCVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/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.

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

No observations available

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

Weakness, pattern, technique

CWE-200Exposure of Sensitive Information to an Unauthorized Actor
CWE-532Insertion of Sensitive Information into Log File
T1552.001Credentials In Files

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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