CyberSecBulletin
CVE-2024-21638NVD status: Modified

ipam: Improper Authentication

CVE-2024-21638 is a critical-severity improper authentication vulnerability in ipam from Azure, 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 ipam versions: < 3.0.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.66% chance of exploitation within 30 days, higher than 77% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update Azure Ipam to 3.0.0 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
Azureipam< 3.0.0Not stated
MicrosoftAzure Ipambefore 3.0.03.0.0

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
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.

Scoring systemScoreSeverityScored by
CVSS 3.19.1CriticalCNA (github.com)
CVSS 3.19.8CriticalNVD

Official description

Azure IPAM (IP Address Management) is a lightweight solution developed on top of the Azure platform designed to help Azure customers manage their IP Address space easily and effectively. By design there is no write access to customers' Azure environments as the Service Principal used is only assigned the Reader role at the root Management Group level. Until recently, the solution lacked the validation of the passed in authentication token which may result in attacker impersonating any privileged user to access data stored within the IPAM instance and subsequently from Azure, causing an elevation of privilege. This vulnerability has been patched in version 3.0.0.

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

The underlying weakness: Improper Authentication

When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.

How developers prevent this class of flaw

  • Use an authentication framework or library such as the OWASP ESAPI Authentication feature.

More Improper Authentication vulnerabilities (CWE-287)

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 Improper Authentication vulnerabilities

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