CVE-2020-8122Network attack vector

Extended share access via unchecked expiration updates

Published Feb 4, 2020 · Updated Aug 4, 2024

Improper access control in Nextcloud Server before 14.0.4 allows remote authenticated users to extend expiration dates on received shares. The server-side share update path accepts and persists a recipient-supplied expiration date without checking share ownership. Recipient access is sufficient to prolong access to shared content beyond the expiration selected by the share owner.

CVSS severity4.3
Medium
EPSS probability0.68%
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 14.0.4 allows remote authenticated users to extend expiration dates on received shares. The server-side share update path accepts and persists a recipient-supplied expiration date without checking share ownership. Recipient access is sufficient to prolong access to shared content beyond the expiration selected by the share owner.

The record

CVE
CVE-2020-8122
Published
Feb 4, 2020
Updated
Aug 4, 2024
Vendor
Nextcloud GmbH
Product
Nextcloud Server
Classifications
CWE-284, CWE-20, T1565.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 4, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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=14.0.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Nextcloud GmbH · Nextcloud Serverversion=14.0.4

Published CVSS scores

4.8Nextcloud GmbHCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
4.3NISTCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
4.0NISTAV:N/AC:L/Au:S/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.

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

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-284Improper Access Control - Generic
CWE-20Improper Input Validation
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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