WA1200: NULL Pointer Dereference
CVE-2026-0731 is a high-severity NULL pointer dereference vulnerability in WA1200 from TOTOLINK, 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 WA1200 versions: 5.9c.2914. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.71% chance of exploitation within 30 days, higher than 54% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of WA1200 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 |
|---|---|---|---|
| TOTOLINK | WA1200 | 5.9c.2914 | Not stated |
| TOTOLINK | Wa1200-poe | Not specified in the record | Not stated |
| TOTOLINK | Wa1200-poe Firmware | 5.9c.2914 | 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
- 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 4.0 | 5.5 | Medium | CNA (vuldb.com) |
| CVSS 3.1 | 5.3 | Medium | CNA (vuldb.com) |
| CVSS 3.1 | 7.5 | High | NVD |
| CVSS 2.0 | 5.0 | Medium | CNA (vuldb.com) |
Official description
A vulnerability has been found in TOTOLINK WA1200 5.9c.2914. The impacted element is an unknown function of the file cstecgi.cgi of the component HTTP Request Handler. The manipulation leads to null pointer dereference. The attack is possible to be carried out remotely. The exploit has been disclosed to the public and may be used.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: NULL Pointer Dereference
The product dereferences a pointer that it expects to be valid but is NULL.
How developers prevent this class of flaw
- For any pointers that could have been modified or provided from a function that can return NULL, check the pointer for NULL before use. When working with a multithreaded or otherwise asynchronous environment, ensure that proper locking APIs are used to lock before the check, and unlock when it has finished.
- Select a programming language that is not susceptible to these issues.
- Check the results of all functions that return a value and verify that the value is non-null before acting upon it.
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
Third-party and government advisories
- vuldb.com/?id.340128Third Party Advisory, VDB Entry
- vuldb.com/?submit.733249Third Party Advisory, VDB Entry
Technical write-ups (may include proof of concept)
- github.com/JackWesleyy/CVE/blob/main/WA1200/TOTOLINK%20WA1200%20NULL%20Pointer%20Dereference%20Vulnerability…Exploit, Third Party Advisory
- github.com/JackWesleyy/CVE/blob/main/WA1200/TOTOLINK%20WA1200%20NULL%20Pointer%20Dereference%20Vulnerability…Exploit, Third Party Advisory
Other references
- vuldb.com/?ctiid.340128Permissions Required, VDB Entry
- totolink.net/Product
Recent NULL Pointer Dereference vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
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