CyberSecBulletin
CVE-2024-32980NVD status: Deferred

spin: Externally Controlled Reference to a Resource in Another Sphere

Published Updated By the CyberSecBulletin desk

CVE-2024-32980 is a critical-severity externally controlled reference to a resource in another sphere vulnerability in spin from Fermyon, with a CVSS 3.1 base score of 9.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected spin versions: < 2.4.3. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.48% chance of exploitation within 30 days, which is low compared with other CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Check which version of spin 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
Fermyonspin< 2.4.3Not 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
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N. Scored by CNA (github.com).

Official description

Spin is the developer tool for building and running serverless applications powered by WebAssembly. Prior to 2.4.3, some specifically configured Spin applications that use `self` requests without a specified URL authority can be induced to make requests to arbitrary hosts via the `Host` HTTP header. The following conditions need to be met for an application to be vulnerable: 1. The environment Spin is deployed in routes requests to the Spin runtime based on the request URL instead of the `Host` header, and leaves the `Host` header set to its original value; 2. The Spin application's component handling the incoming request is configured with an `allow_outbound_hosts` list containing `"self"`; and 3. In reaction to an incoming request, the component makes an outbound request whose URL doesn't include the hostname/port. Spin 2.4.3 has been released to fix this issue.

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

The underlying weakness: Externally Controlled Reference to a Resource in Another Sphere

The product uses an externally controlled name or reference that resolves to a resource that is outside of the intended control sphere.

More Externally Controlled Reference to a Resource in Another Sphere vulnerabilities (CWE-610)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Externally Controlled Reference to a Resource in Another Sphere vulnerabilities

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