CVE-2022-39330

Nextcloud Server is the file server software for Nextcloud, a self-hosted productivity platform. Nextcloud Server prior to versions 23.0.10 and 24.0.6 and Nextcloud Enterprise Server prior to versions 22.2.10, 23.0.10, and 24.0.6 are vulnerable to a logged-in attacker slowing down the system by generating a lot of database/cpu load. Nextcloud Server versions 23.0.10 and 24.0.6 and Nextcloud Enterprise Server versions 22.2.10, 23.0.10, and 24.0.6 contain patches for this issue. As a workaround, disable the Circles app.

Weakness

The product does not properly control the allocation and maintenance of a limited resource.

Affected Software

Potential Mitigations

• Mitigation of resource exhaustion attacks requires that the target system either:

• The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.

• The second solution is simply difficult to effectively institute – and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/147.html
• https://cwe.mitre.org/data/definitions/227.html
• https://cwe.mitre.org/data/definitions/492.html

References

• https://github.com/nextcloud/circles/pull/1147
• https://github.com/nextcloud/security-advisories/security/advisories/GHSA-wxx7-w5p4-7x4c
• https://hackerone.com/reports/1688199
• https://github.com/nextcloud/circles/pull/1147
• https://github.com/nextcloud/security-advisories/security/advisories/GHSA-wxx7-w5p4-7x4c
• https://hackerone.com/reports/1688199