CVE-2021-37273

CVE-2021-37273 is a high-severity vulnerability in Chinatelecom Epon Tianyi Gateway Zxhn F450 Firmware with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Description

A Denial of Service issue exists in China Telecom Corporation EPON Tianyi Gateway ZXHN F450(EPON ONU) 3.0. Tianyi Gateway is a hardware terminal of "Optical Modem Smart Router." Attackers can use this vulnerability to restart the device multiple times.

Frequently asked questions

What is CVE-2021-37273?
A Denial of Service issue exists in China Telecom Corporation EPON Tianyi Gateway ZXHN F450(EPON ONU) 3.0. Tianyi Gateway is a hardware terminal of "Optical Modem Smart Router." Attackers can use this vulnerability to restart the device multiple times.
How severe is CVE-2021-37273?
CVE-2021-37273 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-37273 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (57th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-37273?
CVE-2021-37273 affects Chinatelecom Epon Tianyi Gateway Zxhn F450 Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-37273?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-37273 published?
CVE-2021-37273 was published on 2021-09-28 and last updated on 2026-06-17.

References

Affected products (1)