Security readout for executives and security teams
Plain-English summary
CVE-2025-25253 is a Fortinet certificate validation flaw affecting ZTNA proxy connections. If an attacker can position themselves between a user and the proxy, they may intercept or tamper with traffic. This is not described as remotely exploitable from anywhere, but it can affect confidentiality and integrity of protected access paths.
Executive priority
Treat this as a near-term remediation item for Fortinet ZTNA environments, especially where remote access protects sensitive systems. It is medium severity, but a successful attack could compromise traffic confidentiality and integrity across trusted access sessions.
Technical view
The issue is CWE-297: improper certificate validation with host mismatch. Affected FortiProxy and FortiOS ZTNA proxy versions may fail to correctly reject mismatched certificates, enabling a man-in-the-middle attacker to interfere with connections. The CVSS 3.1 score is 6.8, with adjacent attack vector and high attack complexity.
Likely exposure
Organizations using FortiOS or FortiProxy ZTNA proxy on the listed 7.6, 7.4, 7.2, or 7.0 release lines should investigate. The bundle also lists FortiPAM 1.4.1, but product-specific impact details are not explained in the provided text.
Exploitation context
The source bundle does not show CISA KEV listing or cited evidence of active exploitation. Exploitation requires an unauthenticated attacker already in a man-in-the-middle position, which raises difficulty but does not remove risk for exposed or high-value access paths.
Researcher notes
Evidence is limited to the source bundle. The vulnerability has high confidentiality, integrity, and availability impact in CVSS, but adjacent attack vector and high attack complexity. Do not assume exploit availability, active campaigns, or specific fixed releases beyond vendor-published guidance.
Mitigation direction
- Inventory FortiOS, FortiProxy, and FortiPAM versions against the affected version list.
- Review Fortinet advisory FG-IR-24-457 for official fixed versions and upgrade guidance.
- Prioritize ZTNA proxy deployments protecting sensitive internal applications or privileged workflows.
- Reduce unnecessary network exposure around affected ZTNA proxy paths where operationally feasible.
- Monitor vendor and Siemens advisory pages for downstream product-specific guidance.
Validation and detection
- Confirm whether ZTNA proxy is enabled on FortiOS or FortiProxy assets.
- Compare installed versions with FortiProxy 7.6.1 and below, 7.4.8 and below, 7.2, and 7.0.
- Compare installed versions with FortiOS 7.6.2 and below, 7.4.8 and below, 7.2, and 7.0.
- Check whether FortiPAM 1.4.1 exists in the environment.
- Review TLS inspection, proxy, and access logs for certificate mismatch or interception anomalies.
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-297: 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-2025-25253 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
- 6.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:R
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:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:R1.65.9fortinetVulnerability scoring details
Base CVSS 3.1 score
6.8MediumVector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:R
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-24-457CVE reference, fortinet
- https://cert-portal.siemens.com/productcert/html/ssa-864900.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.
Improper Validation of Certificate with Host Mismatch
Improper Validation of Certificate with Host Mismatch represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.