What's the vulnerability?
Affected versions of cti-transmute contain an SSRF vulnerability in the /fetch_misp_event and /misp_search_events endpoints. The URL validation routine checked whether a supplied hostname was itself an IP literal and rejected private, loopback, link-local, or reserved IPs. However, ordinary domain names were accepted without resolving them first. An attacker could therefore use a hostname whose DNS record pointed to an internal address and cause the cti-transmute server to issue requests into its internal network. The commit explicitly states that anonymous callers could make the server request the internal target and read the response. The fix resolves hostnames using socket.getaddrinfo(), checks that every resolved address is globally routable, and additionally places @login_required on both affected MISP fetch/search routes.
Business impact & how R4IM helps
This advisory is on our active-exploitation watchlist. Attackers are using it for initial access, privilege escalation or lateral movement in real-world intrusions. R4IM's offensive security and SOC teams already have detections, exploit replicas and remediation playbooks for this issue.
Targeted vulnerability assessment to confirm which of your assets are actually exploitable — not just theoretically affected.
Our pentesters chain this CVE into realistic attack paths so you see business impact, not just a scan finding.
If the affected product is internet-facing, our AppSec team will harden it against this and related OWASP-class issues.
Continuous monitoring with custom detections for this CVE deployed across your endpoints, identity and cloud.
Recommended remediation
- Inventory all assets running the affected vendor and product, including shadow IT and third-party hosted instances.
- Apply the vendor patch or mitigation referenced in the advisories below. Where no patch exists, isolate the asset or restrict network exposure.
- Hunt for indicators of prior compromise — exploitation of this class of bug often predates public disclosure.
- Deploy detections for the exploit primitives (network signature, EDR rule, WAF rule) and re-test after remediation.
Need help executing these steps? Our team typically completes validation and remediation within a single patch cycle. Request remediation support →
Vendor & research references
- https://github.com/MISP/cti-transmute/commit/4d29109a6f185d5e7c7f3b906f822ab34403f512 · 5a6e4751-2f3f-4070-9419-94fb35b644e8