FreeScout Authentication and XSS Flaws

Insecure token generation in FreeScout <1.8.213 allows unauthenticated remote attackers to download private email attachments by forging MD5-based download tokens. The predictable formula (md5(APP_KEY + sequential_attachment_id + guessable_size)) enables enumeration of all stored attachments without credentials. CVSS 8.8 reflects high confidentiality and integrity impact via network vector with no authentication required. EPSS data not provided. Proof-of-concept exploitation exists (E:P in CVSS vector). Vendor-released patch version 1.8.213 available via GitHub.

CSS injection in FreeScout mailbox signatures enables CSRF token exfiltration and privilege escalation from authenticated agents to administrators. The vulnerability exists in FreeScout versions prior to 1.8.213 where incomplete input sanitization fails to strip <style> tags from mailbox signature fields. Attackers with mailbox configuration access leverage CSS attribute selectors to steal CSRF tokens from viewing users, then perform arbitrary state-changing actions including admin account creation. EPSS data not available; no confirmed active exploitation (CISA KEV absent). Vendor patch released in version 1.8.213 with complete fix addressing previous incomplete remediation (GHSA-jqjf-f566-485j).