Detections
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SCA: security update for flarum/sticky (GHSA-h3gg-7wx2-cq3h)
medium Tenable Cloud Security Plugin ID 415431
Description
There are packages installed that are affected by a vulnerability referenced in the following CVE:- Flarum is an open source discussion platform for websites. The "Flarum Sticky" extension versions
0.1.0-beta.14 and 0.1.0-beta.15 has a cross-site scripting vulnerability. A change in release beta 14 of
the Sticky extension caused the plain text content of the first post of a pinned discussion to be injected
as HTML on the discussion list. The issue was discovered following an internal audit. Any HTML would be
injected through the m.trust() helper. This resulted in an HTML injection where <script> tags would not be
executed. However it was possible to run javascript from other HTML attributes, enabling a cross-site
scripting (XSS) attack to be performed. Since the exploit only happens with the first post of a pinned
discussion, an attacker would need the ability to pin their own discussion, or be able to edit a
discussion that was previously pinned. On forums where all pinned posts are authored by your staff, you
can be relatively certain the vulnerability has not been exploited. Forums where some user-created
discussions were pinned can look at the first post edit date to find whether the vulnerability might have
been exploited. Because Flarum doesn't store the post content history, you cannot be certain if a
malicious edit was reverted. The fix will be available in version v0.1.0-beta.16 with Flarum beta 16. The
fix has already been back-ported to Flarum beta 15 as version v0.1.0-beta.15.1 of the Sticky extension.
Forum administrators can disable the Sticky extension until they are able to apply the update. The
vulnerability cannot be exploited while the extension is disabled. (CVE-2021-21283)
See Also
Plugin Details
Severity: Medium
ID: 415431
Version: Revision 1.7
Type: Local
Family: SCA Checks
Published: 1/23/2025
Updated: 7/2/2026
Supported Sensors: Tenable Cloud Security, Tenable Self-Hosted Container Security
Risk Information
VPR
Risk Factor: Low
Score: 2.3
Percentile: 8.67
Vendor
Vendor Severity: Medium
CVSS v2
Risk Factor: Low
Base Score: 3.5
Temporal Score: 2.6
Vector: CVSS2#AV:N/AC:M/Au:S/C:N/I:P/A:N
CVSS Score Source: CVE-2021-21283
CVSS v3
Risk Factor: Medium
Base Score: 5.4
Temporal Score: 4.7
Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C
Vulnerability Information
Exploit Ease: No known exploits are available
Patch Publication Date: 1/29/2021
Vulnerability Publication Date: 1/26/2021
Reference Information
CVE: CVE-2021-21283
cwe: CWE-79