CVE-2023-49791Network attack vector

Workflow modification via missing API password confirmation

Published Dec 22, 2023 · Updated Sep 12, 2024

Improper access control in Nextcloud Server before 26.0.9 and 27.1.4 allows remote authenticated users to alter workflows via API calls. The workflow engine's AWorkflowController and UserWorkflowsController create, update, and destroy methods omit server-side password confirmation, so direct requests bypass the UI check. An attacker must first obtain another user's active session; successful requests can modify or delete that user's workflow configuration.

CVSS severity5.4
Medium
EPSS probability0.61%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper access control in Nextcloud Server before 26.0.9 and 27.1.4 allows remote authenticated users to alter workflows via API calls. The workflow engine's AWorkflowController and UserWorkflowsController create, update, and destroy methods omit server-side password confirmation, so direct requests bypass the UI check. An attacker must first obtain another user's active session; successful requests can modify or delete that user's workflow configuration.

The record

CVE
CVE-2023-49791
Published
Dec 22, 2023
Updated
Sep 12, 2024
Vendor
Nextcloud GmbH
Product
Security Advisories
Classifications
CWE-287, CWE-284, T1565.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 22, 2023CVE publishedPublication date reported by the CVE source.
  2. Sep 12, 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=>= 23.0.0, < 23.0.12.13
  2. Affected versionversion=>= 24.0.0, < 24.0.12.9
  3. Affected versionversion=>= 25.0.0, < 25.0.13.4
  4. Affected versionversion=>= 26.0.0, < 26.0.9
  5. Affected versionversion=>= 27.0.0, < 27.1.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Nextcloud GmbH · Security Advisoriesversion=>= 23.0.0, < 23.0.12.13; version=>= 24.0.0, < 24.0.12.9; version=>= 25.0.0, < 25.0.13.4; version=>= 26.0.0, < 26.0.9; version=>= 27.0.0, < 27.1.4

Published CVSS scores

5.4GitHubCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L

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)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-287Improper Authentication
CWE-284Improper Access Control
T1565.001Stored Data Manipulation

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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