Zoom Desktop Client for Windows, Zoom VDI…: Improper Handling of Unicode Encoding
CVE-2024-24691 is a critical-severity improper handling of unicode encoding vulnerability in Zoom Desktop Client for Windows, Zoom VDI Client for Windows, and Zoom Meeting SDK for Windows from Zoom Video Communications, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Zoom Desktop Client for Windows, Zoom VDI Client for Windows, and Zoom Meeting SDK for Windows versions: see references. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.7% chance of exploitation within 30 days, higher than 78% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Meeting Software Development Kit to 5.16.5 or a later version.
- Update Rooms to 5.17.0 or a later version.
- Update Vdi Windows Meeting Clients to 5.14.14 or 5.15.12 or 5.16.10, whichever matches your release line, or a later version.
- Read the advisory on zoom.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Zoom Video Communications | Zoom Desktop Client for Windows, Zoom VDI Client for Windows, and Zoom Meeting SDK for Windows | see references | Not stated |
| Zoom | Meeting Software Development Kit | before 5.16.5 | 5.16.5 |
| Zoom | Rooms | before 5.17.0 | 5.17.0 |
| Zoom | Vdi Windows Meeting Clients | before 5.14.14; after 5.14.14 up to, but not including, 5.15.12; after 5.15.12 up to, but not including, 5.16.10 | 5.14.14, 5.15.12, 5.16.10 |
| Zoom | Zoom | before 5.16.5 | 5.16.5 |
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
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 9.6 | Critical | CNA (zoom.us) |
| CVSS 3.1 | 9.8 | Critical | NVD |
Official description
Improper input validation in Zoom Desktop Client for Windows, Zoom VDI Client for Windows, and Zoom Meeting SDK for Windows may allow an unauthenticated user to conduct an escalation of privilege via network access.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Handling of Unicode Encoding
The product does not properly handle when an input contains Unicode encoding.
How developers prevent this class of flaw
- Avoid making decisions based on names of resources (e.g. files) if those resources can have alternate names.
- Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.
More Improper Handling of Unicode Encoding vulnerabilities (CWE-176)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
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