CVE-2023-35391: ASP.NET Core SignalR and Visual Studio Information Disclosure Vulnerability

Overview

Severity
Medium (CVSS 6.2)
CVSS Vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:P/RL:O/RC:C
Category
Information Disclosure
Exploit Status
Not Exploited
Exploitation Likelihood
Less Likely
Patch Tuesday
2023-Aug
Released
2023-08-08
Last Updated
2023-10-17
EPSS Score
2.01% (percentile: 83.7%)

FAQ

What type of information could be disclosed by this vulnerability? This vulnerability makes it possible to listen to any group or user with a specially crafted group/username. By exploiting this vulnerability, the attacker can now receive messages for group(s) that they are unauthorized to view. According to the CVSS metric, the attack vector is local (AV:L). Why does the CVE title indicate that this is information disclosure? The attack itself is carried out locally. For example, when the score indicates that the Attack Vector is Local (AV:L) and User Interaction is Required (UI:R), this could describe an exploit in which an attacker, through social engineering, convinces a victim to download and run a malicious application. This could lead to a local attack on the user's device which could leak data.

Affected Products (6)

Developer Tools

  • Microsoft Visual Studio 2022 version 17.2
  • Microsoft Visual Studio 2022 version 17.4
  • Microsoft Visual Studio 2022 version 17.6
  • ASP.NET Core 2.1
  • .NET 6.0
  • .NET 7.0

Security Updates (6)

Acknowledgments

Brennan Conroy

Revision History

  • 2023-08-08: Information published.
  • 2023-10-17: Updated one or more CVSS scores for the affected products and added an FAQ explaining the vector string settings. This is an informational change only.