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CVE Record

CVE-2021-31249: A CRLF injection vulnerability was found on BF-430, BF-431, and BF-450M TCP/IP Converter devices from CHIYU...

A CRLF injection vulnerability was found on BF-430, BF-431, and BF-450M TCP/IP Converter devices from CHIYU Technology Inc due to a lack of validation on the parameter redirect= available on multiple CGI components.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

This vulnerability affects named CHIYU TCP/IP converter devices and stems from unsafe handling of a redirect parameter. An attacker could potentially tamper with HTTP responses. The public bundle does not provide CVSS, confirmed impact depth, or active exploitation evidence.

Executive priority

Prioritize remediation for exposed or operationally sensitive CHIYU converters. Business urgency is unclear without severity scoring, but internet-facing embedded device management interfaces should not remain broadly reachable.

Technical view

CVE-2021-31249 is a CRLF injection issue in BF-430, BF-431, and BF-450M CHIYU TCP/IP Converter devices. The cited description attributes it to missing validation of the redirect= parameter across multiple CGI components. Exact affected firmware versions and fixed versions are not provided in the bundle.

Likely exposure

Exposure is most likely where CHIYU BF-430, BF-431, or BF-450M web management interfaces are reachable by untrusted users, especially over the internet or shared networks.

Exploitation context

The vulnerability is publicly disclosed and described in researcher materials. The bundle does not cite CISA KEV listing, in-the-wild exploitation, exploit maturity, authentication requirements, or weaponized activity.

Researcher notes

Evidence supports CRLF injection through redirect= on multiple CGI components, but the bundle lacks CVSS, CWE mapping, authentication context, affected firmware ranges, and exact fixed versions. Treat vendor guidance as authoritative before declaring remediation complete.

Mitigation direction

  • Identify any BF-430, BF-431, or BF-450M devices in the environment.
  • Check CHIYU firmware guidance and apply vendor-recommended updates where applicable.
  • Restrict device web administration to trusted management networks or VPN.
  • Remove internet exposure for device administration interfaces.
  • Segment these converters from user networks and high-value systems.

Validation and detection

  • Inventory model numbers and firmware versions for all CHIYU converter devices.
  • Confirm whether device web interfaces are reachable from untrusted networks.
  • Review CHIYU firmware update guidance for applicable device versions.
  • Perform only authorized, non-destructive response-header validation in a lab.
  • Check logs for unusual redirect parameter values, if logging is available.
Prepared
Confidence
medium
Sources
5

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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CVE-2021-31249 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

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.

0CVSS vectors
0Timeline events
0ADP providers
4Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/an/an/aListed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.