Zoom for Windows Client: Improper Verification of Cryptographic Signature
CVE-2023-28602 is a high-severity improper verification of cryptographic signature vulnerability in Zoom for Windows Client from Zoom Video Communications, with a CVSS 3.1 base score of 7.7 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 Zoom for Windows Client versions: before 5.13.5. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.31% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Zoom to 5.13.5 or a later version.
- Read the advisory on explore.zoom.us for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Zoom Video Communications | Zoom for Windows Client | before 5.13.5 | Not stated |
| Zoom | Zoom | before 5.13.5 | 5.13.5 |
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
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 2.8 | Low | CNA (zoom.us) |
| CVSS 3.1 | 7.7 | High | NVD |
Official description
Zoom for Windows clients prior to 5.13.5 contain an improper verification of cryptographic signature vulnerability. A malicious user may potentially downgrade Zoom Client components to previous versions.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Verification of Cryptographic Signature
The product does not verify, or incorrectly verifies, the cryptographic signature for data.
More Improper Verification of Cryptographic Signature vulnerabilities (CWE-347)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Other vulnerabilities in Zoom for Windows Client
- 7.8 High severity
Recent Improper Verification of Cryptographic Signature vulnerabilities
- 8.8 High severity
- 9.1 Critical severity
- 7.8 High severity
- 7.5 High severity
- 9.8 Critical severity
- 7.8 High severity
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