AshPostgres empty, atomic, non-bulk actions, policy bypass for side-effects vulnerability.

published 2024-10-23 2 y ago modified 2026-06-17 4 mo ago also EUVD-2024-3055 , GHSA-hf59-7rwq-785m

cvss: 5.3; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.5%; EPSS 0.5% chance of exploitation in 30 days, percentile 43%
public exploits: 0; none known

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.

Patch / fix

fixed in 2 links 1

hex ash_postgres 2.4.10
ash_framework ashpostgres 2.4.10

github.com/ash-project/ash_postgres@1228fcd commit

CISA SSVC

Exploitation: Proof of concept is public
Automatable: yes
Technical impact: partial
Assessed: 2 y ago (2024-10-24)

Exploit prediction

0.51% chance of exploitation in the next 30 days, higher than 43% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	5.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
GitHub	3.1	5.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Affected packages

ecosystem	package	affected	fixed in
hex	ash_postgres	>=2.0.0, <2.4.10	2.4.10

Affected products

ash-project ash_postgres
ash_framework ashpostgres

Classification

Weakness

CWE-552 Files or Directories Accessible to External Parties

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.

Summary