Medium severity · published Oct 23, 2024
CVE-2024-49756
AshPostgres empty, atomic, non-bulk actions, policy bypass for side-effects vulnerability.
5.3
CVSS
0.5%
EPSS
No
On KEV
Description
AshPostgres is the PostgreSQL data layer for Ash Framework. Starting in version 2.0.0 and prior to version 2.4.10, in certain very specific situations, it was possible for the policies of an update action to be skipped. This occurred only on "empty" update actions (no changing fields), and would allow their hooks (side effects) to be performed when they should not have been. Note that this does not allow reading new data that the user should not have had access to, only triggering a side effect a user should not have been able to trigger.
To be vulnerable, an affected user must have an update action that is on a resource with no attributes containing an "update default" (updated_at timestamp, for example); can be performed atomically; does not have `require_atomic? false`; has at least one authorizer (typically `Ash.Policy.Authorizer`); and has at least one `change` (on the resource's `changes` block or in the action itself). This is where the side-effects would be performed when they should not have been.
This problem has been patched in `2.4.10` of `ash_postgres`. Several workarounds are available. Potentially affected users may determine that none of their actions are vulnerable using a script the maintainers provide in the GitHub Security Advisory, add `require_atomic? false` to any potentially affected update action, replace any usage of `Ash.update` with `Ash.bulk_update` for an affected action, and/or add an update timestamp to their action.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 44% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AS
ash_postgres · ash-project
>= 2.0.0, < 2.4.10 · source: vendor
AS
Ashpostgres · Ash Framework
through 2.0.0; before 2.4.10 · source: CISA
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2024-49756
CVE.org
https://www.cve.org/CVERecord?id=CVE-2024-49756
elixirforum.com
https://elixirforum.com/t/empty-update-action-with-policies/66954
gist.github.com
https://gist.github.com/zachdaniel/e49166b765978c48dfaf998d06df436e
github.com
https://github.com/ash-project/ash_postgres/commit/1228fcd851f29a68609e236f7d6a2622a4b5c4ba
github.com
https://github.com/ash-project/ash_postgres/security/advisories/GHSA-hf59-7rwq-785m
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