Security readout for executives and security teams
Plain-English summary
A FortiOS HTTP parsing flaw can let an unauthenticated attacker pass an HTTP request through firewall policy handling without normal logging. The direct impact is limited integrity impact, not stated data theft or outage, but it affects perimeter security controls and audit visibility.
Executive priority
Treat this as a targeted perimeter-control issue, not a crisis by itself. Schedule prompt remediation for exposed FortiOS devices because the flaw can undermine firewall policy enforcement and logging confidence.
Technical view
CVE-2025-55018 is CWE-444 HTTP request smuggling in Fortinet FortiOS. Affected FortiOS branches include 7.6.0, 7.4.0-7.4.9, all 7.2 and 7.0 versions, and 6.4.3-6.4.16. CVSS is 5.2 with network access, low complexity, no authentication, changed scope, and low integrity impact.
Likely exposure
Exposure is most relevant where affected FortiOS devices inspect, proxy, or enforce firewall policies for HTTP traffic. Internet-facing or partner-facing paths deserve earlier review because exploitation requires only network access and no credentials.
Exploitation context
The bundle does not show CISA KEV listing or cited in-the-wild exploitation. The CVSS temporal metric indicates proof-of-concept-level exploit maturity, but no operational exploit details are provided here.
Researcher notes
Evidence is sufficient for affected version triage and high-level impact. The bundle does not include fixed version details, detection logic, or exploit telemetry. Avoid assuming broader Fortinet product impact beyond FortiOS unless vendor advisories state it.
Mitigation direction
- Review Fortinet FG-IR-25-667 for fixed versions and supported upgrade paths.
- Upgrade affected FortiOS versions according to Fortinet guidance.
- Prioritize internet-facing FortiOS devices handling HTTP policy enforcement.
- Check Siemens SSA-975644 if Siemens-managed products depend on affected Fortinet components.
- Increase monitoring for HTTP policy bypass indicators until remediation is complete.
Validation and detection
- Inventory FortiOS versions across firewalls and security appliances.
- Match versions against the affected ranges listed in CVE-2025-55018.
- Confirm whether affected devices process untrusted HTTP traffic.
- Verify FortiGuard guidance has been applied after upgrade or mitigation.
- Review logs for unexplained HTTP policy outcomes, noting requests may be unlogged.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-444: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2025-55018 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.2 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N/E:P/RL:O/RC:C
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N/E:P/RL:O/RC:C3.91.4fortinetVulnerability scoring details
Base CVSS 3.1 score
5.2MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N/E:P/RL:O/RC:C
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://fortiguard.fortinet.com/psirt/FG-IR-25-667CVE reference, fortinet
- https://cert-portal.siemens.com/productcert/html/ssa-975644.htmlCVE reference, siemens-SADP
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.