CyberSecBulletin
CVE-2023-40020NVD status: Modified

PrivateUploader: Improper Authentication

CVE-2023-40020 is a high-severity improper authentication vulnerability in PrivateUploader, with a CVSS 3.1 base score of 8.3 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected PrivateUploader versions: < 3.2.49. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.49% 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 PrivateUploader 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.

Affected products and versions

VendorProductAffected versionsFixed in
PrivateUploaderPrivateUploader< 3.2.49Not 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
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
LowSome restricted data 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:L/UI:N/S:U/C:L/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.19.9CriticalCNA (github.com)
CVSS 3.18.3HighNVD

Official description

PrivateUploader is an open source image hosting server written in Vue and TypeScript. In affected versions `app/routes/v3/admin.controller.ts` did not correctly verify whether the user was an administrator (High Level) or moderator (Low Level) causing the request to continue processing. The response would be a 403 with ADMIN_ONLY, however, next() would call leading to any updates/changes in the route to process. This issue has been addressed in version 3.2.49. 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: 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: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Improper Authentication vulnerabilities

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