VMware vCenter Server (vCenter Server): Out-of-bounds Read
CVE-2023-20896 is a high-severity out-of-bounds read vulnerability in VMware vCenter Server (vCenter Server) from VMware, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 8.0 U1b, 7.0 u3m as the first without the flaw, so updating VMware vCenter Server (vCenter Server) to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.9% chance of exploitation within 30 days, higher than 60% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update VMware vCenter Server (vCenter Server) to 8.0 U1b or 7.0 u3m, whichever matches your release line, or a later version.
- Update VMware Cloud Foundation (vCenter Server) to 7.0 U3m, 8.0 U1b or a later version.
- Update Vcenter Server to 7.0 or a later version.
- Read the advisory on vmware.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| VMware | VMware vCenter Server (vCenter Server) | 8.0 up to, but not including, 8.0 U1b; 7.0 up to, but not including, 7.0 u3m | 8.0 U1b, 7.0 u3m |
| VMware | VMware Cloud Foundation (vCenter Server) | 5.x up to, but not including, 7.0 U3m, 8.0 U1b; 4.x up to, but not including, 7.0 U3m, 8.0 U1b | 7.0 U3m, 8.0 U1b |
| VMware | Vcenter Server | 4.0 up to, but not including, 7.0; 7.0; 8.0 | 7.0 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 5.9 | Medium | CNA (vmware.com) |
| CVSS 3.1 | 7.5 | High | NVD |
Official description
The VMware vCenter Server contains an out-of-bounds read vulnerability in the implementation of the DCERPC protocol. A malicious actor with network access to vCenter Server may trigger an out-of-bounds read by sending a specially crafted packet leading to denial-of-service of certain services (vmcad, vmdird, and vmafdd).
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Read
The product reads data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that provides appropriate memory abstractions.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in VMware vCenter Server (vCenter Server)
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
Recent Out-of-bounds Read vulnerabilities
- 7.7 High severity
- 9.1 Critical severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.1 High severity
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