CVE-2023-28835

Insecure randomness for default password in nextcloud

HIGH

7.5

CVSS Score

Published: March 30, 2023 at 06:57 PM UTC

Updated: June 17, 2026 at 05:48 AM UTC

1 product affected across 1 vendorNextcloud/server

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Severity

HIGH7.5

Exploit prediction

EPSS 0.5%

SSVC

No known exploit

Description

Nextcloud server is an open source home cloud implementation. In affected versions the generated fallback password when creating a share was using a weak complexity random number generator, so when the sharer did not change it the password could be guessable to an attacker willing to brute force it. It is recommended that the Nextcloud Server is upgraded to 24.0.10 or 25.0.4. This issue only affects users who do not have a password policy enabled, so enabling a password policy is an effective mitigation for users unable to upgrade.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Nextcloud/server · Nextcloudnextcloud-app

95%

23.0.0 ≤ v < 23.0.1424.0.0 ≤ v < 24.0.1025.0.0 ≤ v < 25.0.4

Affected range stops below 23.0.14, so it looks safe — our inference, not a vendor statement

Affected range stops below 24.0.10, so it looks safe — our inference, not a vendor statement

Affected range stops below 25.0.4, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

References (2)

x_refsource_CONFIRMVendor Advisory

Source: [email protected]

https://github.com/nextcloud/security-advisories/security/advisories/GHSA-7w2p-rp9m-9xp9

x_refsource_MISCIssue TrackingPatch

Source: [email protected]

https://github.com/nextcloud/server/pull/36093

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGH[email protected]

Attack Vector: NETWORK
Complexity: LOW
Privileges: NONE
User Interaction: NONE
Scope: UNCHANGED
Confidentiality: HIGH
Integrity: NONE
Availability: NONE

Vector?

Quick Info

StatusMODIFIED

CWE

CWE-338

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