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DNS pin middleware can be tricked into DNS rebinding allowing SSRF

Moderate
nickvergessen published GHSA-8f69-f9jg-4x3v Nov 21, 2023

Package

Server (Nextcloud)

Affected versions

>= 25.0.0, >= 26.0.0, >= 27.0.0

Patched versions

25.0.11, 26.0.6, 27.1.0
Server (Nextcloud Enterprise)
>= 22.0.0, >= 23.0.0, >= 24.0.0, >= 25.0.0, >= 26.0.0, >= 27.0.0
22.2.10.16, 23.0.12.11, 24.0.12.7, 25.0.11, 26.0.6, 27.1.0

Description

Impact

The DNS pin middleware was vulnerable to DNS rebinding allowing an attacker to perform SSRF as a final result.

Patches

It is recommended that the Nextcloud Server is upgraded to 25.0.11, 26.0.6 or 27.1.0
It is recommended that the Nextcloud Enterprise Server is upgraded to 22.2.10.16, 23.0.12.11, 24.0.12.7, 25.0.11, 26.0.6 or 27.1.0

Workarounds

  • No workaround available

References

For more information

If you have any questions or comments about this advisory:

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Changed
Confidentiality
Low
Integrity
None
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N

CVE ID

CVE-2023-48306

Weaknesses