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Ash Authentication has flawed token revocation checking logic in actions generated by `mix ash_authentication.install`

Moderate severity GitHub Reviewed Published Feb 11, 2025 in team-alembic/ash_authentication • Updated Feb 11, 2025

Package

erlang ash_authentication (Erlang)

Affected versions

>= 4.1.0, < 4.4.9

Patched versions

4.4.9

Description

Impact

Applications which have been bootstrapped by the new igniter installer (since AshAuthentication v4.1.0) and who have used the magic link strategy, password resets, confirmation, or are manually revoking tokens are affected by revoked tokens being allowed to verify as valid. If you did not use the new installer, then you are absolutely not affected.

Additionally, unless you have implemented any kind of custom token revocation feature in your application (in which case even cursory testing would have uncovered this issue), then you will not be significantly affected.

The impact here for users is as follows:

  • For users using the magic link strategy, magic link tokens are reusable until they expire instead of being immediately revoked. By default magic link tokens are valid for 10 minutes.
  • For users of password resets in the password strategy, password reset tokens are reusable until they expire instead of being immediately revoked. By default password reset tokens are valid for 3 days.
  • For users of the confirmation add-on, confirmation tokens are reusable until they expire instead of being immediately revoked. By default password reset tokens are valid for 3 days.

Patches

The flaw is patched in version 4.4.9. Additionally a compile time warning is shown to users with remediation instructions if they upgrade. 4.4.9 ships with an upgrader, so if you use mix igniter.upgrade ash_authentication the necessary patch will be applied for you. Otherwise you can run the upgrader manually as described in the error message

Example

[warning] Warning while compiling Tunez.Accounts.Token:

The `:jti` and `:token` options to the `:revoked?` action must allow nil values and it must return a `:boolean`.

This was an error in our igniter installer previous to version 4.4.9, which allowed revoked tokens to be reused.

To fix this, run the following command in your shell:

    mix ash_authentication.upgrade 4.4.8 4.4.9

Or:

  - remove `allow_nil?: false` from these action arguments, and
  - ensure that the action returns `:boolean`.

  like so:

    action :revoked?, :boolean do
      description "Returns true if a revocation token is found for the provided token"
      argument :token, :string, sensitive?: true
      argument :jti, :string, sensitive?: true

      run AshAuthentication.TokenResource.IsRevoked
    end

Workarounds

Delete the generated :revoked? generic action in your token resource This will cause it to use the one internal to AshAuthentication which has always been correct. Alternatively, manually make the changes described above.

References

See the #ash_authentication channel on the Ash Discord.

References

@zachdaniel zachdaniel published to team-alembic/ash_authentication Feb 11, 2025
Published to the GitHub Advisory Database Feb 11, 2025
Reviewed Feb 11, 2025
Published by the National Vulnerability Database Feb 11, 2025
Last updated Feb 11, 2025

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 v4 base metrics

Exploitability Metrics
Attack Vector Network
Attack Complexity High
Attack Requirements None
Privileges Required None
User interaction None
Vulnerable System Impact Metrics
Confidentiality Low
Integrity Low
Availability None
Subsequent System Impact Metrics
Confidentiality None
Integrity None
Availability None

CVSS v4 base metrics

Exploitability Metrics
Attack Vector: This metric reflects the context by which vulnerability exploitation is possible. This metric value (and consequently the resulting severity) will be larger the more remote (logically, and physically) an attacker can be in order to exploit the vulnerable system. The assumption is that the number of potential attackers for a vulnerability that could be exploited from across a network is larger than the number of potential attackers that could exploit a vulnerability requiring physical access to a device, and therefore warrants a greater severity.
Attack Complexity: This metric captures measurable actions that must be taken by the attacker to actively evade or circumvent existing built-in security-enhancing conditions in order to obtain a working exploit. These are conditions whose primary purpose is to increase security and/or increase exploit engineering complexity. A vulnerability exploitable without a target-specific variable has a lower complexity than a vulnerability that would require non-trivial customization. This metric is meant to capture security mechanisms utilized by the vulnerable system.
Attack Requirements: This metric captures the prerequisite deployment and execution conditions or variables of the vulnerable system that enable the attack. These differ from security-enhancing techniques/technologies (ref Attack Complexity) as the primary purpose of these conditions is not to explicitly mitigate attacks, but rather, emerge naturally as a consequence of the deployment and execution of the vulnerable system.
Privileges Required: This metric describes the level of privileges an attacker must possess prior to successfully exploiting the vulnerability. The method by which the attacker obtains privileged credentials prior to the attack (e.g., free trial accounts), is outside the scope of this metric. Generally, self-service provisioned accounts do not constitute a privilege requirement if the attacker can grant themselves privileges as part of the attack.
User interaction: This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable system. This metric determines whether the vulnerability can be exploited solely at the will of the attacker, or whether a separate user (or user-initiated process) must participate in some manner.
Vulnerable System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the VULNERABLE SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the VULNERABLE SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the VULNERABLE SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
Subsequent System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the SUBSEQUENT SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the SUBSEQUENT SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the SUBSEQUENT SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(11th percentile)

Weaknesses

CVE ID

CVE-2025-25202

GHSA ID

GHSA-qrm9-f75w-hg4c

Source code

Credits

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