GHSA-jm79-9pm4-vrw9 — high GitHub Advisory (CVE-2023-34090) in rubygems/decidim

Description

Note: added the actual report as a comment.

Summary

Decidim, a platform for digital citizen participation, uses a third-party library named Ransack for filtering certain database collections (e.g., public meetings). By default, this library allows filtering on all data attributes and associations. This allows an unauthenticated remote attacker to exfiltrate non-public data from the underlying database of a Decidim instance (e.g., exfiltrating data from the user table).

Impact

This issue may lead to Sensitive Data Disclosure.

Patches

The problem was patched in v0.27.3.

Workarounds

Disable or unpublish all meetings components from your application.

Basic information

Type: reviewed
Severity: high
Advisory on GitHub: Open advisory ↗
Repository advisory: Open repository advisory ↗
Source code: Browse source ↗
Published (advisory): 2023-07-11 22:46:51 UTC
Updated: 2023-11-06 05:05:00 UTC
GitHub reviewed: 2023-07-11 22:46:51 UTC
NVD published: 2023-07-11

Score	Percentile
0.32%	55.23%

CVSS Scores

Base score	Version	Severity	Vector
7.5	3.1	—	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:N) Service keeps running; no real outage angle.

Identifiers

Type	Value
GHSA	GHSA-jm79-9pm4-vrw9 ↗
CVE	CVE-2023-34090 ↗

CWEs

CWE id	Name
CWE-200	Exposure of Sensitive Information to an Unauthorized Actor

Credits

p- (reporter)
ahukkanen (remediation_developer)
alecslupu (remediation_reviewer)

Affected packages (2)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem	Package	Vulnerable range	First patched	Vulnerable functions
rubygems	decidim	>= 0.27.0, < 0.27.3	0.27.3	—
rubygems	decidim-meetings	>= 0.27.0, < 0.27.3	0.27.3	—

Decidim vulnerable to sensitive data disclosure