Security readout for executives and security teams
Plain-English summary
This CVE describes a denial-of-service issue in the China Telecom Tianyi Gateway ZXHN F450 EPON ONU 3.0. The reported impact is repeated device restarts, which could interrupt connectivity for users or sites relying on the gateway. Public source data does not provide severity scoring, patch status, or attack prerequisites.
Executive priority
Treat this as an availability risk for sites dependent on the affected gateway. Prioritize confirming whether the model exists in your environment, then seek provider guidance. Urgency increases if devices support business-critical connectivity or are reachable from untrusted networks.
Technical view
The CVE record states that attackers can trigger repeated restarts of a Tianyi Gateway ZXHN F450 EPON ONU 3.0 device. The source bundle does not include CVSS, CWE, CPE, root cause, authentication requirements, affected firmware range beyond 3.0, or vendor remediation details.
Likely exposure
Exposure is most relevant to environments using the specified China Telecom EPON optical modem smart router model and version. The sources do not state whether exploitation requires local network access, management interface access, or internet exposure.
Exploitation context
CISA KEV status is false in the supplied bundle. The provided sources do not cite active exploitation, public exploit availability, or observed campaigns. The only stated attacker outcome is repeated device restart.
Researcher notes
The public record is sparse. It identifies a denial-of-service restart impact but omits exploit vector, authentication state, vulnerable component, patch status, and scoring. Avoid assuming broader ZTE or China Telecom product impact beyond the named Tianyi Gateway ZXHN F450 EPON ONU 3.0.
Mitigation direction
- Identify whether ZXHN F450 EPON ONU 3.0 devices are deployed.
- Check China Telecom, ZTE, or CNVD guidance for firmware or replacement instructions.
- Restrict gateway management access to trusted administrative networks.
- Monitor affected devices for unexpected reboot loops or uptime drops.
- Use provider-supported replacement if no maintained firmware is available.
Validation and detection
- Confirm model and firmware version from asset records or device administration pages.
- Review network inventory for China Telecom Tianyi Gateway deployments.
- Check device uptime and logs for repeated unexplained restarts.
- Verify management interfaces are not exposed to untrusted networks.
- Track the CNVD reference and CVE record for remediation updates.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CVE-2021-37273 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://www.cnvd.org.cn/flaw/show/2958526CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.