Evidence used
- No CISA KEV confirmation is currently recorded.
- The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
- EPSS is 1.69% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2021
CVE-2021-27408High confidence
n/a Welch Allyn medical device management tools — Out-of-bounds Read
Unknown · Welch Allyn medical device management tools
7.5HighCVSS 3.1
Within 7 days
Mitigation availableHigh technical severity; prioritise exposed affected systems while verifying vendor guidance.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityHigh→Operational priority:High, unchanged from published severity.unchanged
Compensating controls
- Apply the linked authoritative mitigation while planning the permanent fix.
- Restrict the affected network interface to trusted sources where business-safe.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs Unknown Welch Allyn medical device management tools and falls inside the recorded affected range.
- Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
High technical severity; prioritise exposed affected systems while verifying vendor guidance.
Mitigation available01
What, why and how
The affected product is vulnerable to an out-of-bounds read, which can cause information leakage leading to arbitrary code execution if chained to the out-of-bounds write vulnerability on the Welch Allyn medical device management tools (Welch Allyn Service Tool: versions prior to v1.10, Welch Allyn Connex Device Integration Suite – Network Connectivity Engine (NCE): versions prior to v5.3, Welch Allyn Software Development Kit (SDK): versions prior to v3.2, Welch Allyn Connex Central Station (CS): versions prior to v1.8.6, Welch Allyn Service Monitor: versions prior to v1.7.0.0, Welch Allyn Connex Vital Signs Monitor (CVSM): versions prior to v2.43.02, Welch Allyn Connex Integrated Wall System (CIWS): versions prior to v2.43.02, Welch Allyn Connex Spot Monitor (CSM): versions prior to v1.52, Welch Allyn Spot Vital Signs 4400 Device (Spot 4400) / Welch Allyn Spot 4400 Vital Signs Extended Care Device: versions prior to v1.11.00).
What
The affected product is vulnerable to an out-of-bounds read, which can cause information leakage leading to arbitrary code execution if chained to the out-of-bounds write vulnerability on the Welch Allyn medical device management tools (Welch Allyn Service Tool: versions prior to v1.10, Welch Allyn Connex Device Integration Suite – Network Connectivity Engine (NCE): versions prior to v5.3, Welch Allyn Software Development Kit (SDK): versions prior to v3.2, Welch Allyn Connex Central Station (CS): versions prior to v1.8.6, Welch Allyn Service Monitor: versions prior to v1.7.0.0, Welch Allyn Connex Vital Signs Monitor (CVSM): versions prior to v2.43.02, Welch Allyn Connex Integrated Wall System (CIWS): versions prior to v2.43.02, Welch Allyn Connex Spot Monitor (CSM): versions prior to v1.52, Welch Allyn Spot Vital Signs 4400 Device (Spot 4400) / Welch Allyn Spot 4400 Vital Signs Extended Care Device: versions prior to v1.11.00).
Why
The product reads data past the end, or before the beginning, of the intended buffer.
How
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may execute code or commands in the affected security context.
What
The affected product is vulnerable to an out-of-bounds read, which can cause information leakage leading to arbitrary code execution if chained to the out-of-bounds write vulnerability on the Welch Allyn medical device management tools (Welch Allyn Service Tool: versions prior to v1.10, Welch Allyn Connex Device Integration Suite – Network Connectivity Engine (NCE): versions prior to v5.3, Welch Allyn Software Development Kit (SDK): versions prior to v3.2, Welch Allyn Connex Central Station (CS): versions prior to v1.8.6, Welch Allyn Service Monitor: versions prior to v1.7.0.0, Welch Allyn Connex Vital Signs Monitor (CVSM): versions prior to v2.43.02, Welch Allyn Connex Integrated Wall System (CIWS): versions prior to v2.43.02, Welch Allyn Connex Spot Monitor (CSM): versions prior to v1.52, Welch Allyn Spot Vital Signs 4400 Device (Spot 4400) / Welch Allyn Spot 4400 Vital Signs Extended Care Device: versions prior to v1.11.00).
Why
The product reads data past the end, or before the beginning, of the intended buffer.
How
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may execute code or commands in the affected security context.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
- Likely attack path
- a network path → Out-of-bounds Read → execute code or commands in the affected security context
- Attack surface
- Network
- Privileges required
- None: unauthenticated exploitation is possible
- User interaction
- None
- Attack complexity
- Low: no specialised conditions are recorded
- Security boundary
- Unchanged: impact remains within the vulnerable component's security authority
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-125 ↗
CWE-125: Out-of-bounds Read. The product reads data past the end, or before the beginning, of the intended buffer.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:NCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.INoneIntegrity impact: No direct loss is represented by this metric.ANoneAvailability impact: No direct loss is represented by this metric.- Post-exploitation / living off the land
- After compromise, an attacker may use built-in shells, scripting engines, scheduled tasks and native network utilities for discovery, persistence or movement. This is a plausible LoTL path, not evidence that it has occurred for every attack.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Mitigation available
- Action
- Apply the mitigation in the linked authoritative guidance while planning the vendor's permanent fix.
- Workaround
- A mitigation or workaround reference is available from the source linked below; validate it against the affected product and version.
04
Evidence and provenance
Published 11 Jun 2021 · Last source change 3 Aug 2024, 20:48 UTC · CWE-125 · Out-of-bounds Read
CVE recordCVE.org · 5.1
CVSS sourceNIST NVD
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2021-14162
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD modified after enrichment
Missing structured fields: affected product. Missing data is not evidence of low risk; review the primary advisory.
Material change intelligence
View recent updates ↗What changed after publication
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.
CVE published
Mitigation reference recorded
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.