Zoom Desktop Client for Windows: Improper Neutralization of Script-Related HTML Tags in a Web Page
CVE-2023-39216 is a critical-severity improper neutralization of script-related HTML tags in a web page vulnerability in Zoom Desktop Client 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 versions: before 5.14.7. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.23% chance of exploitation within 30 days, higher than 69% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Zoom to 5.14.7 or a later version.
- Read the advisory on explore.zoom.us 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 | before 5.14.7 | Not stated |
| Zoom | Zoom | before 5.14.7 | 5.14.7 |
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 before 5.14.7 may allow an unauthenticated user to enable 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 Neutralization of Script-Related HTML Tags in a Web Page
The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special characters such as <, >, and & that could be interpreted as web-scripting elements when they are sent to a downstream component that processes web pages.
How developers prevent this class of flaw
- With Struts, write all data from form beans with the bean's filter attribute set to true.
More Improper Neutralization of Script-Related HTML Tags in a Web Page vulnerabilities (CWE-80)
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
Other vulnerabilities in Zoom Desktop Client for Windows
- 7.8 High severity
- 8.8 High severity
- 7.8 High severity
- 9.8 Critical severity
- 8.8 High severity
Recent Improper Neutralization of Script-Related HTML Tags in a Web Page vulnerabilities
- 7.5 High severity
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