Security readout for executives and security teams
Plain-English summary
CVE-2023-34048 is a critical VMware vCenter Server flaw that can allow remote code execution by an unauthenticated attacker with network access to vCenter. Because vCenter controls virtualization infrastructure and CISA lists this CVE as exploited, exposed or unpatched deployments should be treated as urgent business risk.
Executive priority
Make this a top-priority infrastructure remediation. Successful exploitation could compromise the virtualization control plane, affecting many dependent servers and services. KEV status means this is not only theoretical risk.
Technical view
The issue is an out-of-bounds write in vCenter Server's DCERPC protocol implementation, classified as CWE-787. The published CVSS 3.1 score is 9.8 with network attack vector, low complexity, no privileges, no user interaction, and high confidentiality, integrity, and availability impact.
Likely exposure
Likely exposure is VMware vCenter Server 8.0 and 7.0, plus VMware Cloud Foundation deployments using vCenter in 5.x and 4.x branches. The key exposure condition is attacker network reachability to vCenter Server.
Exploitation context
CISA KEV inclusion supports known exploitation. The provided sources do not include exploit mechanics, public proof-of-concept status, or observed campaign details. Treat internet-reachable or broadly reachable vCenter management services as highest priority.
Researcher notes
Evidence supports unauthenticated network-based RCE potential via DCERPC out-of-bounds write. The bundle does not provide vulnerable build ranges, fixed build numbers, detection signatures, or exploit telemetry beyond CISA KEV listing.
Mitigation direction
- Apply VMware guidance from VMSA-2023-0023 for affected vCenter and Cloud Foundation deployments.
- Confirm exact fixed builds and upgrade paths with VMware before deployment.
- Restrict vCenter management access to trusted administrative networks only.
- Prioritize remediation for internet-facing or widely reachable vCenter instances.
Validation and detection
- Inventory vCenter Server and VMware Cloud Foundation versions across all environments.
- Check whether each deployment matches affected 8.0, 7.0, 5.x, or 4.x entries.
- Verify patch or upgrade status against VMware VMSA-2023-0023.
- Review network reachability to vCenter management services from untrusted networks.
- Monitor for unusual vCenter crashes, service instability, or unauthorized administrative activity.
Public sources used
Michael Williams reviewed this cited source version on .
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-787: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. 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 lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2023-34048 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
- Critical
- CVSS
- 9.8 (3.1)
- Known Exploited
- Yes
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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.
CISA KEV status
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:H/I:H/A:H3.95.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://www.vmware.com/security/advisories/VMSA-2023-0023.htmlCVE reference
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-34048CVE reference · government-resource
- https://www.vicarius.io/vsociety/posts/understanding-cve-2023-34048-a-zero-day-out-of-bound-write-in-vcenter-serverCVE reference
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.
Out-of-bounds Write
Out-of-bounds Write represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.