CVE-2025-4496: A vulnerability was found in TOTOLINK T10, A3100R, A950RG, A800R, N600R, A3000RU and A810R 4.1.8cu.5241_B20210
48
This month
HIGH 8.8MITIGATEMITIGATEMITIGATE
CVE-2025-4496 is a high-severity flaw (CVSS 8.8) affecting a3000ru firmware, a810r firmware, t10 firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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 this priority
High severity
No fix is published yet: follow the downgrade or mitigation steps.
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
Published CVE record published
Updated Record last modified
totolink a3000ru firmware MITIGATE
Affected: 4.1.8cu.5241_b20210927
Fixed in: no fixed release known
Safe to downgrade to: a release before 4.1.8cu.5241_b20210927
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
totolink a810r firmware MITIGATE
Affected: 4.1.8cu.5241_b20210927
Fixed in: no fixed release known
Safe to downgrade to: a release before 4.1.8cu.5241_b20210927
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
totolink t10 firmware MITIGATE
Affected: 4.1.8cu.5241_b20210927
Fixed in: no fixed release known
Safe to downgrade to: a release before 4.1.8cu.5241_b20210927
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
totolink a3100r firmware MITIGATE
Affected: 4.1.8cu.5241_b20210927
Fixed in: no fixed release known
Safe to downgrade to: a release before 4.1.8cu.5241_b20210927
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
totolink a950rg firmware MITIGATE
Affected: 4.1.8cu.5241_b20210927
Fixed in: no fixed release known
Safe to downgrade to: a release before 4.1.8cu.5241_b20210927
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
totolink a800r firmware MITIGATE
Affected: 4.1.8cu.5241_b20210927
Fixed in: no fixed release known
Safe to downgrade to: a release before 4.1.8cu.5241_b20210927
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
Verify at the official sourceNVD · CVE Program · Report a problem with this page Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2025-4496?
a3000ru firmware: mitigate or apply the listed mitigation; a810r firmware: mitigate or apply the listed mitigation; t10 firmware: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.
Is CVE-2025-4496 being exploited?
CVE-2025-4496 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2025-4496 affect?
CVE-2025-4496 affects a3000ru firmware, a810r firmware, t10 firmware. Severity is high (CVSS 8.8). 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.cg
How urgent is CVE-2025-4496?
Priority 48/100. High severity
Related CVEs
CVE-2025-2955MEDIUM 5.3UPGRADE A vulnerability has been found in TOTOLINK A3000RU up to 5.9c.5185 and classified as problematic
CVE-2025-2688MEDIUM 4.3UPGRADE A vulnerability classified as problematic was found in TOTOLINK A3000RU up to 5.9c.5185
CVE-2025-28036CRITICAL 9.8MITIGATEMITIGATE TOTOLINK A950RG V4.1.2cu.5161_B20200903 was found to contain a pre-auth remote command execution vulnerability
CVE-2025-28035CRITICAL 9.8MITIGATEMITIGATE TOTOLINK A830R V4.1.2cu.5182_B20201102 was found to contain a pre-auth remote command execution vulnerability
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