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SAML IdP Confusion

High
comawill published GHSA-gq27-gmgq-fmxw Oct 18, 2022

Package

wire-server (wire)

Affected versions

< 2022-07-12 or < 4.19.0

Patched versions

>= 2022-07-12 or >=4.19.0

Description

Impact

If an attacker gains knowledge of certain details of SAML IdP metadata of a team and is able to configure SAML SSO for its own team on the same backend, then the attacker can:

  1. Delete all SAML authenticated accounts of the attacked team
  2. Authenticate as user from existing accounts from the attacked team (only if the account authenticates via SAML)
  3. Create arbitrary accounts in the context of the team (only if the attacked team is not managed by SCIM)

Patches

  • The issue is fixed in wire-server 2022-07-12 and is already deployed on all Wire managed services.
  • On-premise instances of wire-server need to be updated to 2022-07-12/Chart 4.19.0, so that their backends are no longer affected.

Workarounds

The risk of an attack can be reduced by disabling SAML configuration for teams (galley.config.settings.featureFlags.sso).
Helm overrides are located in values/wire-server/values.yaml

Note
The ability to configure SAML SSO as a team is disabled by default for on-premise installations.

For more information

If you have any questions or comments about this advisory feel free to email us at [email protected]

Severity

High

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
High
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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:H/PR:N/UI:N/S:U/C:H/I:H/A:H

CVE ID

CVE-2022-31122

Weaknesses

No CWEs