CriticalCISA KEVExploited in the wildPublic exploit

Unauthenticated RCE in VMware vCenter Server DCERPC

IdentifiersCVE-2023-34048CWE-787· Out-of-bounds Write

CVE-2023-34048 is a critical VMware vCenter Server vulnerability caused by an out-of-bounds write in vCenter Server’s implementation of the DCE/RPC (DCERPC) protocol. A remote attacker with network access to the vCenter Server can send specially crafted network traffic that triggers memory corruption, resulting in process instability or crash behavior and potentially enabling remote code execution. Supporting reporting in the provided content associates exploitation with crashes of the vmdird service shortly before attacker deployment of backdoors, and characterizes the flaw as enabling unauthenticated remote command execution on vulnerable systems. The vulnerability was patched in October 2023, including in vCenter 8.0 U2 per the cited reporting.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation can allow an unauthenticated remote attacker to execute commands or arbitrary code on the vulnerable vCenter Server. Because vCenter is the management plane for VMware virtualization environments, compromise can lead to takeover of the virtualization management layer, theft of service account credentials such as vpxuser, access to connected ESXi hosts, deployment of persistent backdoors, tampering with logs, and follow-on compromise of guest virtual machines and broader infrastructure.

Mitigation

If you can’t patch tonight, do this now.

If immediate patching is not possible, reduce exposure by strictly limiting network access to vCenter Server to trusted administrative networks, VPNs, or jump hosts, and ensure it is not exposed to the public internet. Monitor for anomalous DCERPC activity and signs of exploitation such as unexpected vmdird crashes, entries in /var/log/vMonCoredumper.log, missing core dumps, and suspicious post-crash command execution or backdoor deployment. Increase scrutiny of vCenter and ESXi administrative activity and rotate sensitive credentials if compromise is suspected.

Remediation

Patch, then assume compromise.

Apply VMware/Broadcom security updates that address CVE-2023-34048. The provided content states the issue was patched in October 2023 and references vCenter 8.0 U2 as containing the fix; organizations should update to the latest supported vCenter Server release and vendor-recommended patch level rather than relying only on the minimum fixed version. Validate that all internet-exposed or internally reachable vCenter instances are upgraded and review vendor advisories for any product-specific upgrade guidance.

PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType

BroadcomCloud Foundationapplication

BroadcomVcenter Serverapplication

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

ACTIVITY FEED

Recent activity

26 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

26 SOURCESView more in app

palo alto networks unit 42 blogNews

Mar 6, 2026

An Investigation Into Years of Undetected Operations Targeting High-Value Sectors

Remote code execution vulnerability in VMware vCenter Server, referenced as being exploited via a custom (Nuitka-compiled) Python executable.

cyfirma newsNews

Feb 20, 2026

Weekly Intelligence Report - 20 February 2026 - CYFIRMA

A vulnerability (unspecified in the content) affecting VMware vCenter Server that is listed as exploited by the threat actor UNC3886/Volt Typhoon.

bleeping computerNews

Feb 9, 2026

Chinese cyberspies breach Singapore's four largest telcos

A VMware vCenter Server vulnerability referenced as a zero-day used by UNC3886 in targeted intrusions.

cyberthroneNews

Jan 24, 2026

CISA KEV Alert: 5 Critical Vulnerabilities Added to Catalog - TheCyberThrone

A referenced prior VMware-related vulnerability associated in the text with China-nexus exploitation; no additional technical details are provided in the content.

+9 more in the timeline

What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which adversaries are exploiting it right now, which detections to deploy, and what to do tonight.

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Exposure mapping

Query your assets running an affected version, and investigate the blast radius.

Threat actor evidence9

Every observed campaign linking this CVE to a named adversary.

Associated malware3

Malware families riding this exploit, with evidence and IOCs.

Detection signatures1

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity12

Community discussion across Reddit, Mastodon, and other social sources.

EXTERNAL REFERENCES

MITRE CVE

cve.org · CVE-2023-34048

NVD

nvd.nist.gov/vuln/detail/CVE-2023-34048

MITRE CWE · CWE-787

Out-of-bounds Write

Vendor Advisory

vmware.com/security/advisories/VMSA-2023-0023.html

Third Party Advisory

vicarius.io/vsociety/posts/understanding-cve-2023-34048-a-zero-day-out-of-bound-write-in-vcenter-server

US Government Resource

cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-34048