CyberSecBulletin
CVE-2023-47630NVD status: Modified

kyverno: Insufficient Verification of Data Authenticity

CVE-2023-47630 is a high-severity insufficient verification of data authenticity vulnerability in kyverno, with a CVSS 3.1 base score of 7.1 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, but only if a user takes part, for example by opening a link or file. Affected kyverno versions: < 1.10.5. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.26% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of kyverno 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. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
Kyvernokyverno< 1.10.5Not 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
HighSuccess depends on conditions outside the attacker's control.
Privileges required
LowA basic user account is enough.
User interaction
RequiredA user must take an action such as opening a file or link.
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:H/PR:L/UI:R/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.17.1HighCNA (github.com)
CVSS 3.17.1HighNVD

Official description

Kyverno is a policy engine designed for Kubernetes. An issue was found in Kyverno that allowed an attacker to control the digest of images used by Kyverno users. The issue would require the attacker to compromise the registry that the Kyverno users fetch their images from. The attacker could then return an vulnerable image to the the user and leverage that to further escalate their position. As such, the attacker would need to know which images the Kyverno user consumes and know of one of multiple exploitable vulnerabilities in previous digests of the images. Alternatively, if the attacker has compromised the registry, they could craft a malicious image with a different digest with intentionally placed vulnerabilities and deliver the image to the user. Users pulling their images by digests and from trusted registries are not impacted by this vulnerability. There is no evidence of this being exploited in the wild. The issue has been patched in 1.10.5. All users are advised to upgrade. There are no known workarounds for this vulnerability.

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

The underlying weakness: Insufficient Verification of Data Authenticity

The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.

More Insufficient Verification of Data Authenticity vulnerabilities (CWE-345)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in kyverno

All kyverno vulnerabilities

Recent Insufficient Verification of Data Authenticity vulnerabilities

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