CVE-2017-18905Network attack vector

Continued account access via undeleted OAuth sessions

Published Jun 19, 2020 · Updated Aug 5, 2024

Insufficient session expiration in Mattermost Server 3.9.1 and earlier and 3.10.0 through 3.10.1 allows remote attackers to retain OAuth access. The OAuth application deletion path removed access-data records but left linked database sessions and cached session tokens valid. Exposure requires Mattermost to act as an OAuth 2.0 service provider and an application to be deleted while issued sessions remain active, preserving authorized actions.

CVSS severity5.3
Medium
EPSS probability0.77%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Insufficient session expiration in Mattermost Server 3.9.1 and earlier and 3.10.0 through 3.10.1 allows remote attackers to retain OAuth access. The OAuth application deletion path removed access-data records but left linked database sessions and cached session tokens valid. Exposure requires Mattermost to act as an OAuth 2.0 service provider and an application to be deleted while issued sessions remain active, preserving authorized actions.

The record

CVE
CVE-2017-18905
Published
Jun 19, 2020
Updated
Aug 5, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-613, T1078
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 19, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 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?

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

5.3GitHub Advisory DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
5.0NVDAV:N/AC:L/Au:N/C:N/I:P/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-613Insufficient Session Expiration
T1078Valid Accounts

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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