CVE-2021-34823

13.08.2021, 17:15

The ON24 ScreenShare (aka DesktopScreenShare.app) plugin before 2.0 for macOS allows remote file access via its built-in HTTP server. This allows unauthenticated remote users to retrieve files accessible to the logged-on macOS user. When a remote user sends a crafted HTTP request to the server, it triggers a code path that will download a configuration file from a specified remote machine over HTTP. There is an XXE flaw in processing of this configuration file that allows reading local (to macOS) files and uploading them to remote machines.

Provider	Type	Base Score	Atk. Vector	Atk. Complexity	Priv. Required	Vector
NIST	NIST	9.1 CRITICAL	NETWORK	LOW	NONE	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
mitre	CNA	---				---
CVE	ADP	---				---

Base Score

CVSS 3.x

EPSS Score

Percentile: 82%

Vendor	Product	Version
on24	screenshare	𝑥 < 2.0

𝑥

= Vulnerable software versions

Common Weakness Enumeration

CWE-611 - Improper Restriction of XML External Entity Reference
The software processes an XML document that can contain XML entities with URIs that resolve to documents outside of the intended sphere of control, causing the product to embed incorrect documents into its output.

References

https://www.trustwave.com/en-us/resources/security-resources/security-advisories/

https://www.trustwave.com/en-us/resources/security-resources/security-advisories/?fid=29105

https://www.trustwave.com/en-us/resources/security-resources/security-advisories/

https://www.trustwave.com/en-us/resources/security-resources/security-advisories/?fid=29105