SMA 100 Series: Stack-based Buffer Overflow
CVE-2025-40596 is a high-severity stack-based buffer overflow vulnerability in SMA 100 Series from SonicWall, with a CVSS 3.1 base score of 7.3 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected SMA 100 Series versions: 10.2.1.15-81sv and earlier versions. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 45.3% chance of exploitation within 30 days, which is in the top 1.19% of all scored CVEs.
EPSS places it among the vulnerabilities most likely to be exploited soon.
What to do
- Update Sma 500v Firmware to 10.2.2.1-90sv or a later version.
- Update Sma 210 Firmware to 10.2.2.1-90sv or a later version.
- Update Sma 410 Firmware to 10.2.2.1-90sv or a later version.
- Read the advisory on psirt.global.sonicwall.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 |
|---|---|---|---|
| SonicWall | SMA 100 Series | 10.2.1.15-81sv and earlier versions | Not stated |
| SonicWall | Sma 500v Firmware | before 10.2.2.1-90sv | 10.2.2.1-90sv |
| SonicWall | Sma 210 Firmware | before 10.2.2.1-90sv | 10.2.2.1-90sv |
| SonicWall | Sma 410 Firmware | before 10.2.2.1-90sv | 10.2.2.1-90sv |
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
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- LowSome restricted data can be read.
- Integrity
- LowLimited modification of data is possible.
- Availability
- LowPerformance or availability is reduced.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L. Scored by CISA (ADP).
Official description
A Stack-based buffer overflow vulnerability in the SMA100 series web interface allows remote, unauthenticated attacker to cause Denial of Service (DoS) or potentially results in code execution.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Stack-based Buffer Overflow
The product writes past the end of a buffer that was allocated on the stack.
How developers prevent this class of flaw
- 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.
- Use an abstraction library to abstract away risky APIs. Not a complete solution.
- Implement and perform bounds checking on input.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other vulnerabilities in SMA 100 Series
- 7.5 High severity
- 9.1 Critical severity
Recent Stack-based Buffer Overflow vulnerabilities
- 9.8 Critical severity
- 7.5 High severity
- 8.7 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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