Fortinet FortiOS and FortiADC Improper Access Control
CVE-2018-13374 is a medium-severity incorrect permission assignment for critical resource vulnerability in Fortinet FortiOS, fortiADC from Fortinet, with a CVSS 3.1 base score of 4.3 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. CISA added it to the Known Exploited Vulnerabilities catalogue on September 8, 2022, which means attacks have been observed in the wild, including in ransomware campaigns.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Update Fortiadc to 5.4.5 or 6.0.2, whichever matches your release line, or a later version.
- Update Fortios to 6.0.3 or a later version.
- CISA's required action: Apply updates per vendor instructions.
- Read the advisory on fortiguard.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Fortinet | Fortinet FortiOS, fortiADC | Not specified in the record | Not stated |
| Fortinet | Fortiadc | 5.4.0 up to, but not including, 5.4.5; 6.0.0 up to, but not including, 6.0.2; 6.1.0 | 5.4.5, 6.0.2 |
| Fortinet | Fortios | before 6.0.3 | 6.0.3 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- LowSome restricted data can be read.
- Integrity
- NoneNothing can be modified.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 4.3 | Medium | CNA (fortinet.com) |
| CVSS 3.1 | 4.3 | Medium | NVD |
| CVSS 2.0 | 4.0 | Medium | NVD |
Official description
A Improper Access Control in Fortinet FortiOS 6.0.2, 5.6.7 and before, FortiADC 6.1.0, 6.0.0 to 6.0.1, 5.4.0 to 5.4.4 allows attacker to obtain the LDAP server login credentials configured in FortiGate via pointing a LDAP server connectivity test request to a rogue LDAP server instead of the configured one.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Incorrect Permission Assignment for Critical Resource
The product specifies permissions for a security-critical resource in a way that allows that resource to be read or modified by unintended actors.
How developers prevent this class of flaw
- When using a critical resource such as a configuration file, check to see if the resource has insecure permissions (such as being modifiable by any regular user), and generate an error or even exit the software if there is a possibility that the resource could have been modified by an unauthorized party.
- Divide the software into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully defining distinct user groups, privileges, and/or roles. Map these against data, functionality, and the related resources. Then set the permissions accordingly. This will allow you to maintain more fine-grained control over your resources.
- During program startup, explicitly set the default permissions or umask to the most restrictive setting possible. Also set the appropriate permissions during program installation. This will prevent you from inheriting insecure permissions from any user who installs or runs the program.
More Incorrect Permission Assignment for Critical Resource vulnerabilities (CWE-732)
Timeline
- CVE record published.
- Added to CISA's Known Exploited Vulnerabilities catalogue.
- Deadline for US federal agencies to remediate, set by CISA.
- CISA published its SSVC assessment (exploitation: active, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Third-party and government advisories
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2018-13374US Government Resource
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