CyberSecBulletin
CVE-2023-34060NVD status: Modified

VMware Cloud Director Appliance (VCD Appliance): Missing Authentication for Critical Functionality

CVE-2023-34060 is a critical-severity missing authentication for critical functionality vulnerability in VMware Cloud Director Appliance (VCD Appliance), with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected VMware Cloud Director Appliance (VCD Appliance) versions: 10.5 if upgraded from 10.4.x or below.. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.34% chance of exploitation within 30 days, higher than 72% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update Cloud Director to 10.5 or a later version.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
VMware Cloud Director Appliance (VCD Appliance)VMware Cloud Director Appliance (VCD Appliance)10.5 if upgraded from 10.4.x or below.Not stated
VMwareCloud Directorbefore 10.510.5

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
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Official description

VMware Cloud Director Appliance contains an authentication bypass vulnerability in case VMware Cloud Director Appliance was upgraded to 10.5 from an older version. On an upgraded version of VMware Cloud Director Appliance 10.5, a malicious actor with network access to the appliance can bypass login restrictions when authenticating on port 22 (ssh) or port 5480 (appliance management console) . This bypass is not present on port 443 (VCD provider and tenant login). On a new installation of VMware Cloud Director Appliance 10.5, the bypass is not present. VMware Cloud Director Appliance is impacted since it uses an affected version of sssd from the underlying Photon OS. The sssd issue is no longer present in versions of Photon OS that ship with sssd-2.8.1-11 or higher (Photon OS 3) or sssd-2.8.2-9 or higher (Photon OS 4 and 5).

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Missing Authentication for Critical Functionality

The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.

How developers prevent this class of flaw

  • For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using libraries with authentication capabilities such as OpenSSL or the ESAPI Authenticator.
  • When storing data in the cloud (e.g., S3 buckets, Azure blobs, Google Cloud Storage, etc.), use the provider's controls to require strong authentication for users who should be allowed to access the data.

More Missing Authentication for Critical Functionality vulnerabilities (CWE-306)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Missing Authentication for Critical Functionality vulnerabilities

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