CyberSecBulletin
CVE-2023-31133NVD status: Modified

Ghost: Exposure of Sensitive Information to an Unauthorized Actor

CVE-2023-31133 is a high-severity exposure of sensitive information to an unauthorized actor vulnerability in Ghost from TryGhost, 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 Ghost versions: < 5.46.1. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 45.7% chance of exploitation within 30 days, which is in the top 1.18% of all scored CVEs.

Patch this week

EPSS places it among the vulnerabilities most likely to be exploited soon.

What to do

  1. Check which version of Ghost 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
TryGhostGhost< 5.46.1Not 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
NoneNothing can be modified.
Availability
NoneAvailability is not affected.

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

Scoring systemScoreSeverityScored by
CVSS 3.17.5HighCNA (github.com)
CVSS 3.17.5HighNVD

Official description

Ghost is an app for new-media creators with tools to build a website, publish content, send newsletters, and offer paid subscriptions to members. Prior to version 5.46.1, due to a lack of validation when filtering on the public API endpoints, it is possible to reveal private fields via a brute force attack. Ghost(Pro) has already been patched. Maintainers can find no evidence that the issue was exploited on Ghost(Pro) prior to the patch being added. Self-hosters are impacted if running Ghost a version below v5.46.1. v5.46.1 contains a fix for this issue. As a workaround, add a block for requests to `/ghost/api/content/*` where the `filter` query parameter contains `password` or `email`.

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

The underlying weakness: Exposure of Sensitive Information to an Unauthorized Actor

The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.

How developers prevent this class of flaw

  • Compartmentalize the system to have safe areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

More Exposure of Sensitive Information to an Unauthorized Actor vulnerabilities (CWE-200)

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

Other vulnerabilities in Ghost

All Ghost vulnerabilities

Recent Exposure of Sensitive Information to an Unauthorized Actor vulnerabilities

Spotted an error? Tell us.