CyberSecBulletin
CVE-2022-24726NVD status: Modified

istio: Uncontrolled Resource Consumption

Published Updated By the CyberSecBulletin desk

CVE-2022-24726 is a high-severity uncontrolled resource consumption vulnerability in istio, 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. Affected istio versions: < 1.11.8,; >= 1.12.0, < 1.12.5; >= 1.13.0, < 1.13.2. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.59% chance of exploitation within 30 days, higher than 76% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of istio you run against the affected versions below, and install the vendor's latest release.
  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
Istioistio< 1.11.8,; >= 1.12.0, < 1.12.5; >= 1.13.0, < 1.13.2Not stated

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 systemScoreSeverityScored by
CVSS 3.17.5HighCNA (github.com)
CVSS 3.17.5HighNVD
CVSS 2.05.0MediumNVD

Official description

Istio is an open platform to connect, manage, and secure microservices. In affected versions the Istio control plane, istiod, is vulnerable to a request processing error, allowing a malicious attacker that sends a specially crafted message which results in the control plane crashing when the validating webhook for a cluster is exposed publicly. This endpoint is served over TLS port 15017, but does not require any authentication from the attacker. For simple installations, Istiod is typically only reachable from within the cluster, limiting the blast radius. However, for some deployments, especially [external istiod](https://istio.io/latest/docs/setup/install/external-controlplane/) topologies, this port is exposed over the public internet. This issue has been patched in versions 1.13.2, 1.12.5 and 1.11.8. Users are advised to upgrade. Users unable to upgrade should disable access to a validating webhook that is exposed to the public internet or restrict the set of IP addresses that can query it to a set of known, trusted entities.

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

The underlying weakness: Uncontrolled Resource Consumption

The product does not properly control the allocation and maintenance of a limited resource.

How developers prevent this class of flaw

  • Ensure that protocols have specific limits of scale placed on them.
  • Ensure that all failures in resource allocation place the system into a safe posture.

More Uncontrolled Resource Consumption vulnerabilities (CWE-400)

Timeline

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

References

Advisories

Patches and release notes

Other vulnerabilities in istio

All istio vulnerabilities

Recent Uncontrolled Resource Consumption vulnerabilities

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