CVE-2025-28034: TOTOLINK A800R V4.1.2cu.5137_B20200730, A810R V4.1.2cu.5182_B20201026, A830R V4.1.2cu.5182_B20201102, A950RG V
62
This week
CRITICAL 9.8REMOTEMITIGATEMITIGATEMITIGATE
CVE-2025-28034 is a critical-severity flaw (CVSS 9.8) affecting a800r firmware, a810r firmware, a830r firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
TOTOLINK A800R V4.1.2cu.5137_B20200730, A810R V4.1.2cu.5182_B20201026, A830R V4.1.2cu.5182_B20201102, A950RG V4.1.2cu.5161_B20200903, A3000RU V5.9c.5185_B20201128, and A3100R V4.1.2cu.5247_B20211129 were found to contain a pre-auth remote command execution vulnerability in the NTPSyncWithHost function through the hostTime parameter.
Why this priority
Critical severity
Public exploit reference
Remotely exploitable, no login, no user action
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 a800r firmware MITIGATE
Affected: 4.1.2cu.5137_b20200730
Fixed in: no fixed release known
Safe to downgrade to: a release before 4.1.2cu.5137_b20200730
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: 4.1.2cu.5182_b20201026
Fixed in: no fixed release known
Safe to downgrade to: a release before 4.1.2cu.5182_b20201026
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 a830r firmware MITIGATE
Affected: 4.1.2cu.5182_b20201102
Fixed in: no fixed release known
Safe to downgrade to: a release before 4.1.2cu.5182_b20201102
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: 4.1.2cu.5161_b20200903
Fixed in: no fixed release known
Safe to downgrade to: a release before 4.1.2cu.5161_b20200903
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 a3000ru firmware MITIGATE
Affected: 5.9c.5185_b20201128
Fixed in: no fixed release known
Safe to downgrade to: a release before 5.9c.5185_b20201128
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: 4.1.2cu.5247_b20211129
Fixed in: no fixed release known
Safe to downgrade to: a release before 4.1.2cu.5247_b20211129
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-2025-28034?
a800r firmware: mitigate or apply the listed mitigation; a810r firmware: mitigate or apply the listed mitigation; a830r firmware: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.
Is CVE-2025-28034 being exploited?
CVE-2025-28034 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-2025-28034 affect?
CVE-2025-28034 affects a800r firmware, a810r firmware, a830r firmware. Severity is critical (CVSS 9.8). TOTOLINK A800R V4.1.2cu.5137_B20200730, A810R V4.1.2cu.5182_B20201026, A830R V4.1.2cu.5182_B20201102, A950RG V4.1.2cu.5161_B20200903, A3000RU V5.9c.5185_B20201128, and A3100R V4.1.2cu.5247_B20211129 were found to contain a pre-auth remote c
How urgent is CVE-2025-28034?
Priority 62/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action
Related CVEs
CVE-2025-4496HIGH 8.8MITIGATEMITIGATE A vulnerability was found in TOTOLINK T10, A3100R, A950RG, A800R, N600R, A3000RU and A810R 4.1.8cu.5241_B20210
CVE-2025-28138CRITICAL 9.8MITIGATE The TOTOLINK A800R V4.1.2cu.5137_B20200730 were found to contain a pre-auth remote command execution vulnerabi
CVE-2025-28136MEDIUM 6.5MITIGATE TOTOLINK A800R V4.1.2cu.5137_B20200730 was found to contain a buffer overflow vulnerability in the downloadFil
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
PatchTheCVE