Ac6 Firmware: Stack-based Buffer Overflow
CVE-2025-70252 is a high-severity stack-based buffer overflow vulnerability in Ac6 Firmware from Tenda, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Ac6 Firmware versions: 15.03.06.23_multi. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.5% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of Ac6 Firmware you run against the affected versions below, and install the vendor's latest release.
- 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 |
|---|---|---|---|
| Tenda | Ac6 Firmware | 15.03.06.23_multi | Not stated |
Version data comes from NVD's product matching. 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
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.5 | High | NVD |
| CVSS 3.1 | 7.5 | High | CISA (ADP) |
Official description
An issue was discovered in /goform/WifiWpsStart in Tenda AC6V2.0 V15.03.06.23_multi. The index and mode are controllable. If the conditions are met to sprintf, they will be spliced into tmp. It is worth noting that there is no size check,which leads to a stack overflow vulnerability.
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: poc, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Technical write-ups (may include proof of concept)
- github.com/akuma-QAQ/CVEreport/tree/main/D-link/CVE-2025-70252Exploit, Third Party Advisory
Other references
Other vulnerabilities in Ac6 Firmware
- 7.2 High severity
- 8.8 High severity
- 7.2 High severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
Recent Stack-based Buffer Overflow vulnerabilities
- 7.8 High severity
- 7.5 High severity
- 9.8 Critical severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
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