Security readout for executives and security teams
Plain-English summary
This vulnerability can let an unauthenticated remote attacker crash NHI’s health insurance web service component, causing service outage until the system is restarted. The published impact is availability loss only, not confirmed data theft or data modification.
Executive priority
Treat this as a high-priority availability risk for any exposed affected service. It is most urgent where service interruption affects patient, insurance, or operational workflows. Prioritize confirmation of exposure and vendor remediation status.
Technical view
CVE-2021-45918 is a heap-based buffer overflow caused by insufficient input string length validation in NHI’s health insurance web service component. CVSS 3.1 is 7.5, network reachable, low complexity, no privileges or user interaction, with high availability impact.
Likely exposure
Exposure is limited to organizations running the named NHI health insurance web service component versions identified by hashes in the advisory. The source bundle provides no CPEs, deployment details, or broader product mapping.
Exploitation context
The sources describe remote unauthenticated denial of service requiring restart for recovery. CISA KEV status is false in the bundle, and no cited source confirms active exploitation or public exploit availability.
Researcher notes
The evidence is sparse: one referenced TWCERT advisory, CVE metadata, hash-like affected versions, and no CPEs. Analysis should avoid assuming code execution, data compromise, or available patches unless official vendor material confirms them.
Mitigation direction
- Check NHI or TWCERT guidance for vendor-approved updates or workarounds.
- Identify and prioritize affected component instances by the listed version hashes.
- Restrict network access to required trusted systems where operationally possible.
- Add monitoring for crashes, restart loops, and abnormal request volume.
- Prepare restart and continuity procedures for affected health service workflows.
Validation and detection
- Inventory deployed NHI health insurance web service components and compare listed version identifiers.
- Confirm whether exposed instances are reachable from untrusted networks.
- Review service logs for crashes or unexplained termination events.
- Verify compensating controls limit unauthenticated access paths.
- Document patch or workaround status from official vendor guidance.
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
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CWE-122: Exact CWE lookup
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Open ATT&CK lookupCVE-2021-45918 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
- High
- CVSS
- 7.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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 vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://www.twcert.org.tw/tw/cp-132-6227-eaf49-1.htmlCVE 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.
Heap-based Buffer Overflow
Heap-based Buffer Overflow represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.