FortiManager: Out-of-bounds Write
CVE-2025-54820 is a high-severity out-of-bounds write vulnerability in FortiManager from Fortinet, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected FortiManager versions: 7.4.0 through 7.4.2; 7.2.0 through 7.2.10; 6.4.0 through 6.4.15. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.97% chance of exploitation within 30 days, higher than 62% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of FortiManager you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on fortiguard.fortinet.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Fortinet | FortiManager | 7.4.0 through 7.4.2; 7.2.0 through 7.2.10; 6.4.0 through 6.4.15 | Not stated |
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
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (fortinet.com).
Official description
A Stack-based Buffer Overflow vulnerability [CWE-121] vulnerability in Fortinet FortiManager 7.4.0 through 7.4.2, FortiManager 7.2.0 through 7.2.10, FortiManager 6.4 all versions may allow a remote unauthenticated attacker to execute unauthorized commands via crafted requests, if the service is enabled. The success of the attack depends on the ability to bypass the stack protection mechanisms.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Write
The product writes data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega, and the Strsafe.h library from Microsoft. These libraries provide safer versions of overflow-prone string-handling functions.
- Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other vulnerabilities in FortiManager
- 9.8 Critical severity
- 7.2 High severity
- 7.2 High severity
- 7.2 High severity
- 7.2 High severity
- 7.5 High severity
Recent Out-of-bounds Write vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 8.4 High severity
- 8.4 High severity
- 9.8 Critical severity
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