Security readout for executives and security teams
Plain-English summary
FortiWAN versions before 4.5.9 stored password hashes using predictable salt. If an attacker already obtained the password file, that weakness could make password guessing easier and expose credentials. This is not described as remote compromise by itself, but it can worsen another breach involving appliance files or backups.
Executive priority
Treat this as a moderate confidentiality risk. It should be scheduled for prompt remediation on affected FortiWAN appliances, especially if backup handling or file access controls are weak. It is not presented as an internet-facing remote takeover, but it can increase credential exposure after another incident.
Technical view
The source describes CWE-760-style use of a one-way hash with predictable salt in Fortinet FortiWAN before 4.5.9. CVSS 3.1 is 6.2 with local attack vector and high confidentiality impact. The core prerequisite is prior possession of the password file; the published data does not describe integrity or availability impact.
Likely exposure
Exposure is limited to Fortinet FortiWAN deployments running versions before 4.5.9. Risk is higher if password files, backups, appliance storage, or administrative archives may have been exposed. Organizations without FortiWAN, or already on 4.5.9 or later, are not indicated as affected by the supplied sources.
Exploitation context
The bundle does not show CISA KEV listing or confirmed active exploitation. Exploitation appears dependent on first obtaining the password file, then attempting offline password guessing. The CVSS vector lists local attack vector and exploit code maturity as proof-of-concept, but no weaponized exploitation details are provided.
Researcher notes
The strongest evidence is the vendor advisory reference and CVE record. The title names CWE-760, while the bundle’s cwes array is empty. Do not claim direct remote exploitation. Focus assessment on version confirmation, password-file exposure paths, backup custody, and whether credentials were reused elsewhere.
Mitigation direction
- Upgrade Fortinet FortiWAN to version 4.5.9 or later.
- Review Fortinet PSIRT FG-IR-21-064 for current vendor guidance.
- Rotate affected passwords if password files or backups may have been exposed.
- Restrict and audit access to appliance files, backups, and administrative archives.
- Use strong unique passwords to reduce offline guessing risk.
Validation and detection
- Inventory FortiWAN appliances and record exact firmware versions.
- Confirm no FortiWAN system remains below version 4.5.9.
- Review backup, file-access, and admin logs for possible password-file exposure.
- Verify password rotation after any suspected password-file compromise.
- Document Fortinet advisory review and remediation status.
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.
Credential and access behavior lookup
The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-26113 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
- 6.2 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:P/RL:U/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.
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:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:P/RL:U/RC:C2.53.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.2MediumVector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:P/RL:U/RC:C
Source materials
- CVE List V5 sourceCVE List V5
- https://fortiguard.com/psirt/FG-IR-21-064CVE reference · x_refsource_CONFIRM
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.