TOTOLINK T10/A3100R/A950RG/A800R/N600R/A3000RU/A810R cstecgi.cgi CloudACMunualUpdate buffer overflow
Priority HIGH 73CWE-119Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-119 and the CVSS impact.
Summary
A vulnerability was found in TOTOLINK T10, A3100R, A950RG, A800R, N600R, A3000RU and A810R 4.1.8cu.5241_B20210927. It has been declared as critical. This vulnerability affects the function CloudACMunualUpdate of the file /cgi-bin/cstecgi.cgi. The manipulation of the argument FileName leads to buffer overflow. The attack can be initiated remotely. The exploit has been disclosed to the public and may be used.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.01231 69th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by the CNA
Fix No fix listed No fixed version in the sources yet
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| TOTOLINK | T10 | 4.1.8cu.5241_B20210927 | — | No fix listed | CNA |
| TOTOLINK | A3100R | 4.1.8cu.5241_B20210927 | — | No fix listed | CNA |
| TOTOLINK | A950RG | 4.1.8cu.5241_B20210927 | — | No fix listed | CNA |
| TOTOLINK | A800R | 4.1.8cu.5241_B20210927 | — | No fix listed | CNA |
| TOTOLINK | N600R | 4.1.8cu.5241_B20210927 | — | No fix listed | CNA |
| TOTOLINK | A3000RU | 4.1.8cu.5241_B20210927 | — | No fix listed | CNA |
| TOTOLINK | A810R | 4.1.8cu.5241_B20210927 | — | No fix listed | CNA |
- T10 VendorTOTOLINK Affected 4.1.8cu.5241_B20210927 Fixed in — No fix listed CNA
- A3100R VendorTOTOLINK Affected 4.1.8cu.5241_B20210927 Fixed in — No fix listed CNA
- A950RG VendorTOTOLINK Affected 4.1.8cu.5241_B20210927 Fixed in — No fix listed CNA
- A800R VendorTOTOLINK Affected 4.1.8cu.5241_B20210927 Fixed in — No fix listed CNA
- N600R VendorTOTOLINK Affected 4.1.8cu.5241_B20210927 Fixed in — No fix listed CNA
- A3000RU VendorTOTOLINK Affected 4.1.8cu.5241_B20210927 Fixed in — No fix listed CNA
- A810R VendorTOTOLINK Affected 4.1.8cu.5241_B20210927 Fixed in — No fix listed CNA
CPE configurations NVD · 14
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:totolink:a3000ru_firmware:4.1.8cu.5241_b20210927:*:*:*:*:*:*:* | 4.1.8cu.5241_b20210927 | Vulnerable | TOTOLINK |
| cpe:2.3:h:totolink:a3000ru:-:*:*:*:*:*:*:* | not specified by NVD | Running on | TOTOLINK |
| cpe:2.3:o:totolink:a810r_firmware:4.1.8cu.5241_b20210927:*:*:*:*:*:*:* | 4.1.8cu.5241_b20210927 | Vulnerable | TOTOLINK |
| cpe:2.3:h:totolink:a810r:-:*:*:*:*:*:*:* | not specified by NVD | Running on | TOTOLINK |
| cpe:2.3:o:totolink:t10_firmware:4.1.8cu.5241_b20210927:*:*:*:*:*:*:* | 4.1.8cu.5241_b20210927 | Vulnerable | TOTOLINK |
| cpe:2.3:h:totolink:t10:-:*:*:*:*:*:*:* | not specified by NVD | Running on | TOTOLINK |
| cpe:2.3:o:totolink:a3100r_firmware:4.1.8cu.5241_b20210927:*:*:*:*:*:*:* | 4.1.8cu.5241_b20210927 | Vulnerable | TOTOLINK |
| cpe:2.3:h:totolink:a3100r:-:*:*:*:*:*:*:* | not specified by NVD | Running on | TOTOLINK |
| cpe:2.3:o:totolink:a950rg_firmware:4.1.8cu.5241_b20210927:*:*:*:*:*:*:* | 4.1.8cu.5241_b20210927 | Vulnerable | TOTOLINK |
| cpe:2.3:h:totolink:a950rg:-:*:*:*:*:*:*:* | not specified by NVD | Running on | TOTOLINK |
- cpe:2.3:o:totolink:a3000ru_firmware:4.1.8cu.5241_b20210927:*:*:*:*:*:*:* Versions 4.1.8cu.5241_b20210927 Vulnerable ·TOTOLINK
- cpe:2.3:h:totolink:a3000ru:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·TOTOLINK
- cpe:2.3:o:totolink:a810r_firmware:4.1.8cu.5241_b20210927:*:*:*:*:*:*:* Versions 4.1.8cu.5241_b20210927 Vulnerable ·TOTOLINK
- cpe:2.3:h:totolink:a810r:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·TOTOLINK
- cpe:2.3:o:totolink:t10_firmware:4.1.8cu.5241_b20210927:*:*:*:*:*:*:* Versions 4.1.8cu.5241_b20210927 Vulnerable ·TOTOLINK
- cpe:2.3:h:totolink:t10:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·TOTOLINK
- cpe:2.3:o:totolink:a3100r_firmware:4.1.8cu.5241_b20210927:*:*:*:*:*:*:* Versions 4.1.8cu.5241_b20210927 Vulnerable ·TOTOLINK
- cpe:2.3:h:totolink:a3100r:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·TOTOLINK
- cpe:2.3:o:totolink:a950rg_firmware:4.1.8cu.5241_b20210927:*:*:*:*:*:*:* Versions 4.1.8cu.5241_b20210927 Vulnerable ·TOTOLINK
- cpe:2.3:h:totolink:a950rg:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·TOTOLINK
Show 4 more CPE
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:totolink:a800r_firmware:4.1.8cu.5241_b20210927:*:*:*:*:*:*:* | 4.1.8cu.5241_b20210927 | Vulnerable | TOTOLINK |
| cpe:2.3:h:totolink:a800r:-:*:*:*:*:*:*:* | not specified by NVD | Running on | TOTOLINK |
| cpe:2.3:o:totolink:n600r_firmware:4.1.8cu.5241_b20210927:*:*:*:*:*:*:* | 4.1.8cu.5241_b20210927 | Vulnerable | TOTOLINK |
| cpe:2.3:h:totolink:n600r:-:*:*:*:*:*:*:* | not specified by NVD | Running on | TOTOLINK |
- cpe:2.3:o:totolink:a800r_firmware:4.1.8cu.5241_b20210927:*:*:*:*:*:*:* Versions 4.1.8cu.5241_b20210927 Vulnerable ·TOTOLINK
- cpe:2.3:h:totolink:a800r:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·TOTOLINK
- cpe:2.3:o:totolink:n600r_firmware:4.1.8cu.5241_b20210927:*:*:*:*:*:*:* Versions 4.1.8cu.5241_b20210927 Vulnerable ·TOTOLINK
- cpe:2.3:h:totolink:n600r:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·TOTOLINK
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2025-4496
- 2026-10-03 Alias added: GHSA-96qf-wf2v-wxvc
References
More TOTOLINK A3000ru Firmware vulnerabilities
- TI-2025-20692 TOTOLINK A950RG V4.1.2cu.5161_B20200903 was found to contain a pre-auth remote command… CVSS 3.1CRITICAL 9.8
- TI-2025-20691 TOTOLINK A830R V4.1.2cu.5182_B20201102 was found to contain a pre-auth remote command… CVSS 3.1CRITICAL 9.8
- TI-2025-20690 TOTOLINK A800R V4.1.2cu.5137_B20200730, A810R V4.1.2cu.5182_B20201026, A830R… CVSS 3.1CRITICAL 9.8
- TI-2022-08824 TOTOLink A3000RU V5.9c.2280_B20180512 was discovered to contain a command injection… CVSS 3.1CRITICAL 9.8
- TI-2025-20689 TOTOLINK A800R V4.1.2cu.5137_B20200730, A810R V4.1.2cu.5182_B20201026, A830R… CVSS 3.1HIGH 7.3
- TI-2025-20688 TOTOLINK A800R V4.1.2cu.5137_B20200730, A810R V4.1.2cu.5182_B20201026, A830R… CVSS 3.1HIGH 7.3
Sources
- CVE-2025-4496 · CVE Program
- CVE-2025-4496 · NVD
- FIRST EPSS
- GHSA-96qf-wf2v-wxvc · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences