CyberSecBulletin
CVE-2023-39520NVD status: Analyzed

cryptomator: Improper Privilege Management

CVE-2023-39520 is a high-severity improper privilege management vulnerability in cryptomator, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. Affected cryptomator versions: <= 1.9.2; 1.9.2 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.33% 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 cryptomator 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
Cryptomatorcryptomator<= 1.9.2; 1.9.2 and earlierNot 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
LocalThe attacker needs local access or must trick a user into running something.
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
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:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.15.5MediumCNA (github.com)
CVSS 3.17.8HighNVD

Official description

Cryptomator encrypts data being stored on cloud infrastructure. The MSI installer provided on the homepage for Cryptomator version 1.9.2 allows local privilege escalation for low privileged users, via the `repair` function. The problem occurs as the repair function of the MSI is spawning an SYSTEM Powershell without the `-NoProfile` parameter. Therefore the profile of the user starting the repair will be loaded. Version 1.9.3 contains a fix for this issue. Adding a `-NoProfile` to the powershell is a possible workaround.

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

The underlying weakness: Improper Privilege Management

The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor.

How developers prevent this class of flaw

  • Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
  • Follow the principle of least privilege when assigning access rights to entities in a software system.
  • Consider following the principle of separation of privilege. Require multiple conditions to be met before permitting access to a system resource.

More Improper Privilege Management vulnerabilities (CWE-269)

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

Other vulnerabilities in cryptomator

All cryptomator vulnerabilities

Recent Improper Privilege Management vulnerabilities

Spotted an error? Tell us.