CVE-2022-39281 is a medium-severity (CVSS 6.5) Improper Input Validation vulnerability in fat_free_crm. A fix is available for fat_free_crm — see the affected versions and patch details below.
Remote Denial of Service via Tasks endpoint in fat_free_crm
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2022-39281.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2022-39281 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
fat_free_crmReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects RubyGems packages — download data is not available via public APIs for these ecosystems.
Description
Impact
An authenticated user can perform a remote Denial of Service attack against Fat Free CRM.
This vulnerability has been assigned the CVE identifier: CVE-2022-39281
Affected versions: All Not affected: None Fixed versions: 0.20.1
All users running an affected release should either upgrade or apply the patch immediately.
Releases
Fixed versions: 0.20.1 and above
Patches
If you are unable to upgrade immediately, you should apply the following patch.
diff --git a/app/models/polymorphic/task.rb b/app/models/polymorphic/task.rb
index d3d5c32c..7cdb24d6 100644
--- a/app/models/polymorphic/task.rb
+++ b/app/models/polymorphic/task.rb
@@ -189,6 +189,7 @@ class Task < ActiveRecord::Base
#----------------------------------------------------------------------------
def self.bucket_empty?(bucket, user, view = "pending")
return false if bucket.blank? || !ALLOWED_VIEWS.include?(view)
+ return false unless Setting.task_bucket.map(&:to_s).include?(bucket.to_s)
if view == "assigned"
assigned_by(user).send(bucket).pending.count
Credits
Thanks to @p- for reporting this and working with us to responsibly disclose this vulnerability.
Further information
If you have any questions or comments about this advisory, please Open an issue in GitHub Issue Tracker
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | fat_free_crm | all versions | 0.20.1bundle update fat_free_crm --conservative |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for fat_free_crm, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update fat_free_crm to 0.20.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-39281 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2022-39281 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2022-39281. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2022-39281 in your dependencies?
O3 Security finds CVE-2022-39281 across RubyGems dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.