FreeScout vulnerable to SSRF via IMAP/SMTP Connection Test Endpoints
Summary
| CVE | CVE-2026-40566 |
|---|---|
| State | PUBLISHED |
| Assigner | GitHub_M |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-04-21 17:16:55 UTC |
| Updated | 2026-04-21 18:16:50 UTC |
| Description | FreeScout is a free self-hosted help desk and shared mailbox. Versions prior to 1.8.213 have a Server-Side Request Forgery (SSRF) vulnerability in the IMAP/SMTP connection test functionality of FreeScout's `MailboxesController`. Three AJAX actions `fetch_test` (line 731), `send_test` (line 682), and `imap_folders` (line 773) in `app/Http/Controllers/MailboxesController.php` pass admin-configured `in_server`/`in_port` and `out_server`/`out_port` values directly to `fsockopen()` via `Helper::checkPort()` and to IMAP/SMTP client connections with zero SSRF protection. There is no IP validation, no hostname restriction, no blocklist of internal ranges, and no call to the project's own `sanitizeRemoteUrl()` or `checkUrlIpAndHost()` functions. The validation block in `connectionIncomingSave()` is entirely commented out. An authenticated admin can configure a mailbox's IMAP or SMTP server to point at any internal host and port, then trigger a connection test. The server opens raw TCP connections (via `fsockopen()`) and protocol-level connections (via IMAP client or SMTP transport) to the attacker-specified target. The response differentiates open from closed ports, enabling internal network port scanning. When the IMAP client connects to a non-IMAP service, the target's service banner or error response is captured in the IMAP debug log and returned in the AJAX response's `log` field, making this a semi-blind SSRF that enables service fingerprinting. In cloud environments, the metadata endpoint at `169[.]254[.]169[.]254` can be probed and partial response data may be leaked through protocol error messages. This is distinct from the `sanitizeRemoteUrl()` redirect bypass (freescout-3) -- different code path, different root cause, different protocol layer. Version 1.8.213 patches the vulnerability. |
Risk And Classification
Primary CVSS: v3.1 4.1 MEDIUM from [email protected]
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:N/A:N
Problem Types: CWE-918 | CWE-918 CWE-918: Server-Side Request Forgery (SSRF)
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 4.1 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:N/A:N |
| 3.1 | CNA | DECLARED | 4.1 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:N/A:N |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
HighUser Interaction
NoneScope
ChangedConfidentiality
LowIntegrity
NoneAvailability
NoneCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:N/A:N
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Freescout-help-desk | Freescout | affected < 1.8.213 | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/freescout-help-desk/freescout/security/advisories/GHSA-fg98-r... | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | github.com | |
| github.com/freescout-help-desk/freescout/releases/tag/1.8.213 | [email protected] | github.com | |
| github.com/freescout-help-desk/freescout/commit/efe82e31b4a0d4c0b20025d0... | [email protected] | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.