Security readout for executives and security teams
Plain-English summary
A spoofing vulnerability in Microsoft Dynamics 365 Field Service can let a low-privileged attacker present untrusted content to another user. Successful exploitation requires user interaction but could expose sensitive information and make limited unauthorized changes. Availability is not affected.
Executive priority
Treat as a high-priority remediation for exposed or broadly accessible Field Service deployments. Prioritize systems processing sensitive customer or operational data. User interaction limits immediacy, but potential high confidentiality impact and cross-scope behavior justify prompt patch verification.
Technical view
CVE-2024-21394 is classified as CWE-79, indicating improper neutralization of input in web content. CVSS 3.1 scores it 7.6: network-accessible, low complexity, low privileges, user interaction required, and changed scope, with high confidentiality and low integrity impact.
Likely exposure
Exposure may exist in affected on-premises Dynamics 365 deployments, particularly where Field Service is reachable by untrusted or lower-privileged users. The bundle inconsistently names version 9.1 while listing version 9.0, so administrators must confirm affected builds through Microsoft guidance.
Exploitation context
The supplied evidence does not establish active exploitation, and the CVE is not listed as KEV in the bundle. Exploitation requires low privileges and user interaction. No exploit method, observed campaign, or public proof of concept is documented in the supplied sources.
Researcher notes
The CVSS vector indicates network attackability, low privileges, required user interaction, changed scope, high confidentiality impact, low integrity impact, and no availability impact. CWE-79 supports a web-content injection interpretation. The supplied affected-product data conflicts between version 9.1 and 9.0; avoid definitive version claims without vendor confirmation.
Mitigation direction
- Review Microsoft’s CVE-2024-21394 advisory for affected builds and the applicable security update.
- Apply the vendor-provided patch using established change-control and backup procedures.
- Restrict untrusted access to affected Field Service deployments until remediation is verified.
- Monitor Microsoft guidance for revisions concerning the inconsistent affected-version information.
Validation and detection
- Inventory on-premises Dynamics 365 and Field Service versions, editions, and installed updates.
- Compare each identified build against Microsoft’s current affected-product and update information.
- Verify the security update installed successfully across all relevant application nodes.
- Review security telemetry for suspicious low-privileged activity involving unexpected web content or user redirection.
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.
CWE-79: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2024-21394 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
- 7.6 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N/E:U/RL:O/RC:C
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.
SSVC decision data
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:L/UI:R/S:C/C:H/I:L/A:N/E:U/RL:O/RC:C2.34.7microsoftVulnerability scoring details
Base CVSS 3.1 score
7.6HighVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N/E:U/RL:O/RC:C
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- Dynamics 365 Field Service Spoofing VulnerabilityCVE reference, microsoft · vendor-advisory, patch
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.
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.